communications
TRANSCRIPT
ACOUSTICS…
Acoustics (C2 Past Board: excel)
ECE Board Exam April 2001What do you call the speed of sound in the study of acoustics? Tempo
ECE Board Exam November 2000In the study of acoustics, the velocity of sound is dependent to one of the following:Properties of the medium
ECE Board Exam Apri1 2000How much bigger in storage capacity has digital video disk (DVD) have over the conventional compact disk (CD)?Around 15 times
ECE Board Exam November 1999A sound intensity that could cause painful sensation In a human earThreshold of pain
ECE Board Exam April 1999Which of the following is the hearing range of the human ear?The range of the human hearing is from 20 Hz to 20 kHz
ECE Board Exam April 1998An instrument for recording waveforms of audio frequency.Phonoscope
ECE Board Exam November 1997/April 2000Designates the sensation of low or high in the sense of the base and treble.Pitch
ECE Board Exam April 1997The sound energy per unit area at right angles to the propagation direction per unit time.Sound intensity
ECE Board Exam November 1996 Speaker is a device that ___________converts current variations into sound waves
ECE Board Exam March 1996One-hundred twenty µbars of pressure variation is equal to
ECE Board Exam April 2000The term that describes the highness or lowness of a sound in the study of acoustics is called aPitch
ECE Board Exam November 1999The method of measuring absorption coefficient of sound which considers all angles of incidence is calledreverberation chamber method
ECE Board Exam March 1996The midrange frequency range of sound is from256 to 2048 Hz
ECE Board Exam November 1997A large speaker having a large diameter (15 cm and above).Woofer
ECE Board Exam April 1997_______ is the transmission of sound from one to an adjacent room thru common walls, floors or ceilings.Flanking transmission
ECE Board Exam November 1996___________ is the advantage rate of transmission of sound energy in a given direction through a cross sectional area of 1 sq. m. at right angle to the direction.Sound intensity
ECE Board Exam November 1997A method of expressing the amplitude of a complex non-periodic signals such as speech.Volume
ECE Board Exam April 1997
The sound power level of a jet plane flying at a height of 1 km is 160 dB (re 10^-12). What is the maximum sound pressure level on the ground directly below the plane assuming that the aircraft radiates sound equally in all directions?
ECE Board Exam November 1996The unit of pitch.Mel
ECE Board Exam November 1997/April 1997The tendency of the sound energy to spread.Diffraction
ECE Board Exam April 1999Which of the following is considered the most commonly used measurable components of sound?Particle displacement
ECE Board Exam April 1997Lowest frequency produced by a musical instrument.Fundamental
ECE Board Exam November 1997 Sound intensity is given asdP/dA
ECE Board Exam April 1997 Tendency of sound energy to spreadDiffraction
ECE Board Exam November 1997The lowest frequency produced by an instrument.Fundamental
ECE Board Exam March 1996A car horn outdoors produces a sound intensity level of 90 dB at 10 ft away. At distance, what is the sound power in watt?
0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Acoustics and Brodcasting, Communications, Past Board
Friday, October 22, 2010
Acoustic & Broadcasting [MITRC refresher]
1. Which best describe the sound wave?a. It may be longitudinalb. It is always transversec. It is always longitudinal d. All of the above
2. Which of the following can not travel through a vacuum?a. Electromagnetic waveb. Radio wavec. Soundwaved. Light wave
3. Through which medium does sound travel fastest?a. Airb. Waterc. Steeld. Mercury
4. Speed that is faster than that of sound.a. Ultrasonicb. Supersonic c. Subsonicd. Transonic
5. What is the speed of sound in air at 20°C?a. 1087 ft/sb. 1100 ft/sc. 1126 ft/sd. 200 ft/s
6. Calculate a half wavelength sound for sound of 16000 Hza. 35 ftb. 10 ftc. 0.035 ftd. 100 ft
7. The lowest frequency that a human ear can hear isa. 5 Hzb. 20 Hzc. 30 Hzd. 20 Hz
8. Sound that vibrates at frequency too high for the human ear to hear (over 20 kHz)a. Subsonicb. Ultrasonicc. Transonicd. Stereo
9. The frequency interval between two sounds whose frequency ratio is 10a. Octaveb. Half octavec. Third-octaved. Decade
10. A 16 KHz sound is how many octaves higher than a 500 Hz sounda. 2b. 5c. 4d. 8
11. Sound waves composed of but one frequency is a/ana. Infra soundb. Pure tonec. Structure borned. Residual sound
12. Sound wave has two main characteristics which are a. Highness and loudnessb. Tone and loudnessc. Pitch and loudnessd. Rarefactions and compressions
13. When waves bend away from straight lines of travel, it is calleda. Reflectionb. Diffractionc. Rarefactiond. Refraction
14. The amplitude of sound waves, the maximum displacement of each air particle, is the property which perceive as _____ of a sounda. Pitchb. Intensityc. Loudnessd. Harmonics
15. It is the weakest sound that average human hearing can detect.a. SPL = 0 dB
b. Threshold of hearingc. Reference pressure = 2 x 10-5N/m2d. A, b, c
16. What is a device that is used to measure the hearing sensitivity of a person?a. Audiometerb. OTDRc. SLMd. Spectrum analyzer
17. What is the device used in measuring sound pressure levels incorporating a microphone, amplification, filtering and a display.a. Audiometerb. OTDRc. SLMd. Spectrum analyzer
18. What weighted scale in a sound level meter gives a reading that is most closely to the response of the human ear?a. Weighted scale Ab. Weighted scale Bc. Weighted scale Cd. Weighted scale D
19. For aircraft noise measurements, the weighting scale that is used is _____.a. Weighted scale Ab. Weighted scale Bc. Weighted scale Cd. Weighted scale D
20. It is the device used to calibrate an SLM?a. Microphoneb. Pistonphonec. Telephoned. Filter
21. _____ is the sound power measured over the area upon which is received.a. Sound pressure b. Sound energyc. Sound intensityd. Sound pressure level
22. A measure of the intensity of sound in comparison to another sound intensitya. Phonb. Decibelc. Pascald. Watts
23. Calculate the sound intensity level in dB of a sound whose intensity is 0.007 W/m2.a. 95 dBb. 91 dBc. 98 dBd. 101 dB
24. What is the sound pressure level for a given sound whose RMS pressure is 200/m2?a. 200 dBb. 20 dBc. 140 dB
d. 14 dB
25. What is the sound intensity for an RMS pressure of 200 Pascal?a. 90 W/m2b. 98 W/m2c. 108 W/m2d. 88 W/m2
26. The sound pressure level is increased by _____ dB if the pressure is doubled.a. 3b. 4c. 5d. 6
27. The sound pressure level is increased by _____ dB if the intensity is doubled.a. 3b. 4c. 5d. 6
28. If four identical sounds are added what is the increase in level in dB?a. 3b. 4c. 5d. 6
29. The transmission of sound from one room to an adjacent room, via common walls, floors or ceilings.a. Flanking transmissionb. Reflectionc. Refractiond. Reverberation
30. _____ is the continuing presence of an audible sound after the sound source has stop.a. Flutter echob. Sound concentrationc. Sound shadowd. Reverberation
31. Required time for any sound to decay to 60 dBa. Echo timeb. Reverberation timec. Delay timed. Transient time
32. A room containing relatively little sound absorption a. Dead roomb. Anechoic roomc. Live roomd. Free-field
33. A room in which the walls offer essentially 100% absorption, therefore simulating free field conditions.a. Dead roomb. Anechoic roomc. Live roomd. Closed room
34. Calculate the reverberation time of the room, which has a volume of 8700 ft3 and total sound absorption 140 sabins.a. 0.3 secb. 3.5 secc. 3 secd. 0.53 sec
35. It is an audio transducer that converts acoustic pressure in air into its equivalent electrical impulsesa. Loudspeakerb. Amplifierc. Baffled. Microphone
36. _____ is a pressure type microphone with permanent coil as a transducing element.a. Dynamicb. Condenserc. Magneticd. Carbon
37. A microphone which has an internal impedance of 25 kΩ is _____ type.a. High impedanceb. Low impedancec. Dynamicd. Magnetic
38. A microphone that uses the piezoelectric effecta. Dynamicb. Condenserc. Crystald. Carbon
39. _____ is a type of loudspeaker driver with an effective diameter of 5 inches used at midrange audio frequency.a. Tweeter b. Wooferc. Mid-ranged. A or C
40. _____ is measure of how much sound is produced from the electrical signal.a. Sensitivityb. Distortionc. Efficiencyd. Frequency response
41. It describes the output of a microphone over a range of frequencies.a. Directivityb. Sensitivityc. Frequency responsed. All of the above
42. A loudspeaker radiates an acoustic power of 1 mW if the electrical input is 10 W. What is its rated efficiency?a. -10 dBb. -20 dB c. -30 dBd. -40 dB
43. An amplifier can deliver 100 W to a loudspeaker. If the rated efficiency of the loudspeaker is -60 dB. What is the maximum intensity 300 ft from it?a. 10 dBb. 20 dBc. 30 dBd. 40 dB
44. Speaker is a device thata. Converts sound waves into current and voltageb. Converts current variations into sound wavesc. Converts electrical energy to mechanical energyd. Converts electrical energy to electromagnetic energy
45. The impedance of most drivers is about _____ ohms at their resonant frequency.a. 4b. 6c. 8d. 10
46. It is a transducer used to convert electrical energy to mechanical energy.a. Microphone b. Baffle c. Magnetic assemble d. Driver
47. It is an enclosure used to prevent front and back wave cancellation.a. Loudspeakerb. Driverc. Baffled. Frame
48. A circuit that divides the frequency components into separate bands in order to have individual feeds to the different drivers.a. Suspension systemb. Dividing networkc. Magnet assemblyd. Panel board
49. _____ is early reflection of sound.a. Echob. Pure soundc. Reverberationd. Intelligible sound
50. Noise reduction system used for film sound in movie.a. Dolbyb. DBxc. dBad. dBk
51. Using a microphone at less than the recommended working distance will create a _____ which greatly increases the low frequency signals.a. Roll-offb. Proximity effectc. Drop outd. None of the choices
52. What is the unit of loudness?
a. Sone b. Phonc. Decibeld. Mel
53. A unit of noisiness related to the perceived noise levela. Noyb. dBc. Soned. Phon
54. What is the loudness level of a 1KHz tone if its intensity is 1 x 10-5W/cm2?a. 100 phonsb. 105 phonsc. 110 phonsd. 100 phons
55. What is the process of sending voice, speech, music or image intended for reception by the general public?a. Navigationb. Telephonyc. Broadcastingd. Mixing
56. What is the frequency tolerance for the RF carrier in the standard AM radio broadcast band?a. Zero b. 20 Hzc. 10 Hzd. 20 KHz
57. The transmitting antenna for an AM broadcast station should have a _____ polarization.a. Verticalb. Horizontalc. Circular d. Elliptical
58. The part of a broadcast day from 6 PM to 6 AM local timea. Daytimeb. Nighttimec. Bed timed. Experimental period 59. The service area where the signal is not subject to fading and co-channel interference.a. Primary Service Area b. Secondary Service Areac. Intermittent Service Aread. Quarternary Service Area
60. It is a resistive load used in place of an antenna to test a transmitter under normal loaded condition without actually radiating the transmitter’s output signal.a. Auxiliary Txb. Main Txc. Secondary Txd. Artificial Antenna
61. The operating power of the auxiliary transmitter shall not be less than _____% or never greater than the authorized operating power of the main transmitter.a. 5b. 10
c. 15d. 20 62. What are the frequency limits of the MF BC band?a. 300-3000 kHzb. 3-30 MHzc. 535-1605 kHzd. 88-108 MHz 63. The center to center spacing between two adjacent stations in the Phil. AM BC band is ____.a. 9 kHzb. 200 kHzc. 36 kHzd. 800 kHz
64. How many AM stations can be accommodated in a 150-kHz bandwidth if the highest modulating frequency is 10 kHz?a. 10b. 15c. 7d. 14
65. Short wave broadcasting operates in what band?a. MFb. HFc. VHFd. VLF
66. What does the acronym STL stand for?a. Station-to-linkb. Signal-to-loss-ratioc. Shout-to-lived. Studio-to-transmitter-link 67. One of the main considerations in the selection of antenna site is (AM)a. Conductivity of the soilb. Height of the terrainc. Elevation of the sited. Accessibility
68. One of the broadcast transmission auxiliary services is:a. Remote pick-upb. STLc. Communication, Coordination and Controld. All of the above
69. What is the spacing between any two adjacent channels in the FM broadcast band?a. 20 KHzb. 36 KHzc. 200 KHzd. 800 KHz
70. The first channel in the FM BC band has a center frequency ofa. 88 MHzb. 88.1 MHzc. 88.3 MHzd. 108 MHz
71. What is the radio transmission of two separate signals, left, and right, used to create a multidimensional effect on the receiver?a. SCA b. Stereo systemc. Pilot transmissiond. Monophonic transmission 72. The carrier frequency tolerance for FM broadcasting is _____.a. 25 kHzb. 2 kHzc. 20 kHzd. 30 kHz
73. What is the modulation used by the stereophonic subcarrier?a. FMb. PMc. ISBd. DSB
74. What is the pilot signal for stereo FM?a. 4.25 MHzb. 10 kHzc. 19 KHzd. 38 KHz
75. With stereo FM transmission, does a monaural receiver produce all the sounds that a stereo does?a. Yes b. No c. Either a or bd. Neither a or b
76. Where is de-emphasis added in a stereo FM system?a. Before the matrix at the TXb. Before the matrix at the RXc. After the matrix at the TXd. After the matrix at the RX
77. Where is the pre-emphasis added in a stereo FM system?a. Before the matrix at the TXb. Before the matrix at the RXc. After the matrix at the TXd. After the matrix at the RX
78. The normal frequency for an SCA subcarrier is _____ KHz.a. 67b. 76c. 38d. 19
79. A monaural FM receiver receives only the _____ signal of a stereo multiplex transmission.a. L + Rb. L – Rc. Both a & bd. 67 KHz
80. When fed to the stereo FM modulator, in what form are the L – R signals?a. AFb. DSBSC
c. 19 kHzd. 38 kHz
81. An additional channel of multiplex information that is authorized by the FCC for stereo FM radio stations to feed services such as commercial-free programming to selected customers.a. STLb. EBSc. EIAd. SCA
82. The class of FM station, which has an authorized radiated power not exceeding 125 KW:a. Class Cb. Class Ac. Class Dd. Class B
83. An FM broadcast station, which has an authorized transmitter power not exceeding 10 KW and ERP not exceeding 30 KW:a. Class Db. Class Cc. Class Ad. Class B
84. A class of FM station which is limited in antenna height of 500 ft. above average terraina. Class Db. Class Cc. Class Ad. Class B
85. What type of broadcast service might have their antennas on top of hills?a. FMb. AMc. TVd. A & C
86. How are guardbands allocated in commercial FM stations?a. 25 kHz on either sides of the transmitting signalb. 50 kHz on each side of the carrierc. 75 kHz deviationd. 15 kHz modulation
87. How many commercial FM broadcast channels can fit into the bandwidth occupied by a commercial TV station?a. 10b. 20c. 30d. 40
88. How many international commercial AM broadcast channels can fit into the bandwidth occupied by a commercial TV station?a. 100b. 200c. 125d. 600
89. What kind of modulation is used for the sound portion of a commercial broadcast TV transmission?a. PM
b. FMc. C3Fd. AM
90. Estimate the bandwidth occupied by the sound portion of a TV transmission in US.a. 25 kHzb. 800 kHzc. 80 kHzd. 200 kHz
91. What is the main reason why television picture signal uses amplitude modulation, while voice is frequency modulated?a. Better efficiencyb. Eliminate attenuation of both video and audioc. Maintain synchronized scanning between transmit and received videod. To minimize interference between signals at received end
92. The picture and sound carrier frequencies in a TV receiver are _____ respectively.a. 41.25 MHz, 45.75 MHzb. 45.25 MHz, 41.75 MHzc. 41.75 MHz, 45.25 MHzd. 45.75 MHz, 41.25 MHz
93. What is the separation between visual and aural carrier in TV broadcasting?a. 1.25 MHzb. 4.5 MHzc. 5.75 MHzd. 0.25 MHz
94. What is the separation between the lower limit of a channel and the aural carrier?a. 1.25 MHzb. 4.5 MHzc. 5.75 MHzd. 0.25 MHz
95. What is the visual carrier for channel 12?a. 205.25 MHzb. 55.25 MHzc. 65.75 MHzd. 59.75 MHz
96. What is the aural carrier for channel 3?a. 61.25 MHzb. 55.25 MHzc. 65.75 MHzd. 59.75 MHz
97. What is color subcarrier for channel 2?a. 68.83 MHzb. 211.25 MHzc. 58.83 MHzd. 214.83 MHz
98. If the sound carrier for UHF channel 23 is 529.75 MHz, what is the frequency of the tuner’s local oscillator, when turned to this channel?a. 571 MHzb. 511 MHzc. 498 MHz
d. 500 MHz
99. What is the frequency tolerance in the color carrier of TV broadcasting?a. 2 kHzb. 20 Hzc. 10 Hzd. 1 kHz
100. What is the exact picture carrier frequency for frequency for channel 7 offset by – 10 KHz?a 175.25 MHzb 175.26 MHzc 174 MHzd 175.24 MHz
101. TV channels 7, 11 and 13 are known as _____.a. Mid band UHFb. Low band UHFc. High band VHFd. low band UHF
102. What is eliminated by using interlaced scanning?a. Noiseb. Excessive BWc. Framed. Flicker
103. What percentage of the primary colors used in color TV are needed to produce the brightest white?
a. 30% red, 59% green, 11% blueb. 33% red, 33% green, 33% bluec. 50% red, 28% green, 22% blued. 58% red, 20% green, 22% blue
104. The color with the most luminance isa. Red b. Yellowc. Green d. Blue
105. Suppose the signal from a color camera has R=0.8, G=0.4 and B=0.2, where 1 represents the maximum signal possible. Determine the value at the luminance signala. 0.498b. 0.254c. 0.1325d. 1.4
106. In the previous problem, calculate the chrominance signala. 0.305b. 0.304c. 0.498d. 0.022
107. The three complementary colors are:a. White, yellow, cyanb. Black, white, grayc. Yellow, magenta, cyand. Violet, indigo, fushcia
108. When the colors Magenta and Yellow are mixed the resultant color is:a. Redb. Whitec. Blued. Green
109. Which of the following consist of two of the three primary colors in television signal? a) red, b) violet, c) yellow, and d) bluea. A and Bb. B and Cc. C and Dd. A and D
110. The studio camera produces a luminance signal that contains information abouta. The musical contentb. The speech contentc. The brightness of the scened. The color content of the scene
111. Brightness variations of the picture information are in which signal?a. Ib. Qc. Yd. Z
112. Which of the following is the color video signal transmitted as amplitude modulation of the 3.58 MHz C signal with bandwidth of 0 to 1.3 MHz?a. I signalb. Q signal c. Y signald. X signal
113. Which of the following is the color video signal transmitted as amplitude modulation of the 3.58 MHz C signal in quadrature with bandwidth of 0 to 0.5 MHz?a. I signal b. Q signalc. Y signald. Z signal
114. The _____ affects the difference between black and white on the picture tube and controls the gain of the video amplifiera. Brightness controlb. Volume control c. Power controld. Contrast control
115. Which of the following is not a requirement for a color TV signal?a. compatibility with b lack and white receiversb. Within 6 MHz bandwidthc. Simulate a wide variety of colorsd. Functional with baron super antenna
116. How many electron beams actually leave the electron gun of a single-gun color CRT?a. 1b. 2c. 3d. 1/3
117. What is the difference between the sound carrier and color subcarrier frequencies?a. 1.25 MHzb. 3.58 MHzc. 4.5 MHzd. 0.92 MHz
118. What does aspect ratio mean?a. Ratio of the screen width to its heightb. Ratio of the screen height to its widthc. Ratio of the screen diagonal to its widthd. Ratio of the screen diagonal to its height
119. What is the aspect ratio for HDTV system?a. 4/3b. 9/7c. 19/6d. 16/9
120. The signal that will give the exact color wavelength is _____.a. Hue b. Saturationc. Carrierd. Monochrome
121. Which of the following represents the intensity of a given color?a. Hueb. Saturationc. Carrierd. Monochrome
122. The _____ ensures that the electron beam will strike the correct phosphor dot on the TV screen.a. Coatingb. Aperture Maskc. Diplexerd. Duplexer
123. In a TV receiver, what is the horizontal signal frequency?a. 30 Hzb. 60 Hzc. 15750 Hzd. 157625 Hz
124. In a TV receiver, what is the vertical signal frequency?a. 30 Hzb. 60 Hzc. 15750 Hzd. 157625 Hz
125. What scheme is employed to cause the electron beam in the TV receiver and the electron beam in the studio camera to track identically?a. Interlacingb. NTSCc. Interleavingd. Transmission of sync pulses
126. Equalizing pulses in TV are sent during a. Horizontal blankingb. Vertical blanking
c. The serrationsd. Equalizing intervals127. What is the return of the electron beam in a CRT from right to left or from bottom to top?a. Relayb. Flybackc. Utilizationd. Resolution
128. What is the North American TV standard video?a. PALb. SECAMc. NTSCd. FCC
129. What is the maximum allowable frequency deviation in the audio section of a TV signal for PAL/SECAM?a. 25 kHzb. 50 kHzc. 75 kHzd. 100 kHz
130. What is the frame frequency in the US TV system?a. 30 Hzb. 60 Hzc. 15750 Hzd. 157625 Hz
131. What is the highest video frequency set by the FCC for commercial TV?a. 4.2 MHzb. 15 MHzc. 6 MHzd. 5.5 MHz
132. What determines the maximum number of vertical picture elements?a. Number of frames per secondb. Number of lines on the screenc. Number of pixelsd. Number of fields per second
133. How many horizontal lines are used to develop a TV raster?a. 615b. 525c. 750d. 15750
134. The channel width in the U.S. TV system is :a. 2 MHzb. 6 MHzc. 7 MHzd. 8 MHz
135. It is the popular TV camera designed with much smaller package and lower cost than its earlier designsa. Image orthiconb. Iconoscopec. Vidicond. Plumbicon
136. In a composite video signal, what is the relationship between the amplitude of the signal and the intensity of the electron beam in the receiver picture tube?a. The greater the amplitude the darker the picture b. The lower the amplitude the darker the picturec. The greater the amplitude the lighter the pictured. No effect
137. If there are 625 lines per TV picture then the number of lines per field are:a. 1250b. 312.5c. 625d. 2500
138. What is the process of placing the chrominance signal in the band space between portions of the luminance signal?a. Interlacingb. Fittingc. Sneakingd. Interleaving
139. How much time elapses between the start of one horizontal sync pulse and the next?a. 10.2 μsb. 63.5 μsc. 16.67 μsd. 100 μs
140. Which of the following frequencies is wrong?a. 15,750 Hz for horizontal sync and scanningb. 60 Hz for vertical sync and scanningc. 31,500 Hz for the equalizing pulses and serrations in the vertical sync pulsed. 31,500 Hz for the vertical scanning frequency
141. The camera tube that uses selenium, arsenic and telluriuma. Plumbiconb. Vidiconc. Saticond. Silicon Vidicon
142. The components of composite video signal are:a. Chroma signalb. Blanking pulsec. Synchronizing pulsed. All of these
143. What is the smallest amount of information that can be displayed on a television screen?a. Blipb. Burstc. Pixeld. Bits
144. It is the quality of the TV picture after imperfectionsa. Aspect ratiob. Utilization ratioc. A1 d. Monochrome
145. What section of a TV receiver determines the bandwidth and produces the most signal gain?a. RF amplifier
b. Audio amplifierc. IF amplifierd. Tuned circuit
AMPLIFIERS…
CHAPTER 14 SPECIAL PURPOSE OP-AMP CIRCUITS
CHAPTER 14 SPECIAL PURPOSE OP-AMP CIRCUITS
1. Provides dc isolation between input and output Isolation amplifier
2. Ratio of the output current to the input voltage Transconductance
3. Transconductance is __________ of an OTA Gain
4. A comparator with hysteresis where the input voltage is large enough to drive the device into its saturated states Schmitt trigger
5. The ______________ of a number is the power to which the base must be raised to get that number. Logarithm
6. An amplifier that produces an output that is proportional to the logarithm of the input. Log amplifier
7. Used in applications where it is necessary to have an output current that is controlled by an input voltage. Voltage-to-current converter
8. The circuit used to detect the peak of the input voltage and store that peak voltage on a capacitor. Peak detector
9. The exponent to which the base e must be raised in order to equal a given quantity. Natural logarithm
10. In an OTA, transconductance varies with _________. Bias current
11. Amplifiers that are often used in HF communication systems, including fiber optics, for
processing wide dynamic range signals. Log and antilog amplifiers
12. The key characterisctic of an instrumentation amplifier CMRR
13. The voltage gain of instrumentation amplifier is set by a Resistor
14. The log amplifier may use the ___________ junction of a BJT in the feedback loop Base-emitter
15. The main purpose of an instrumentation amplifier is to amplify _____ signals that are riding on _____ common-mode voltages. small, large
16. The ___________ of an OTA is the input voltage times the transconductance Output current
17. The operation of log and antilog amplifiers is based on the __________ characteristics of a pn junction Nonlinear (logarithmic)
18. A log amplifier has a pn junction in the feedback loop, and an antilog amplifier has a pn junction in __________ with the input Series
19. In a peak detector, an op-amp is used as a __________ to charge a capacitor through a diode to the peak value of the input voltage. Comparator
20. A basic instrumentation amplifier is formed by three op-amps and ________ resistors, including the gain setting resistor. Seven (7)
21. An oscillator that can be either amplitude or pulse modulated by the signal from the input amplifier High-frequency oscillator 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 13 BASIC OP-AMP CIRCUITS
CHAPTER 13 BASIC OP-AMP CIRCUITS
1. A common interfacing process often used when a linear analog system must provide inputs to a digital system. A/D conversion
2. Method of A/D conversion that uses parallel comparators to compare the linear input signal with various reference voltages developed by a voltage divider Flash
3. Produces an output that is proportional to the rate of change of the input voltage Differentiator
4. The difference between the UTP and the LTP Hysteresis voltage
5. Used to generate pulse waveform from the sine wave output of the audio generator. Voltage comparator
6. When the output is at the maximum positive voltage and the input exceeds UTP, the output switches to the _________ negative voltage Maximum
7. Uses a capacitor in the feedback path which is open to dc. This implies that the gain at dc is the open-loop gain of the op-amp. Practical integrator
8. Gives an op-amp noise immunity Hysteresis
9. Used to detect positive and negative voltages by connecting a fixed reference voltage source to the inverting input of a zero-level detector. Nonzero-Level detection
10. A good example of hysteresis Thermostat
11. A comparator with three trigger points Schmitt Trigger
12. The output of Schmitt trigger is Pulse waveform
13. In a comparator with output bounding, what type of diode is used in the feedback loop? Zener
14. Necessary components for the design of a bounded comparator Rectifier and zener diodes
15. Type of circuit that uses comparators Nonzero-level detector
16. Variations of the basic summing amplifier Averaging and scaling amplifier
17. Differentiation of a ramp input produces a step output with an amplitude proportional to the _________ Slope
18. Another term for flash Simultaneous
19. Integration of a step input produces a ramp output with the slope proportional to the _________ Amplitude 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 12 THE OPERATIONAL AMPLIFIER
CHAPTER 12 THE OPERATIONAL AMPLIFIER
1. The measure of an amplifier’s ability to reject common-mode signals CMRR
2. It is the typical value of input offset voltage in the ideal case. 0 V
3. It is the dc current required by the inputs of the amplifier to properly operate the first stage. Input bias current
4. It is the resistance viewed from the output terminal of the op-amp Output impedance
5. The total resistance between the inverting and noninverting inputs Differential input impedance
6. Differential impedance is measured by determining the change in ___________ for a given change in differential input voltage.
Bias current
7. Common temperature coefficient for the offset current 0.5nA/°C
8. Functions of negative feedback in an op-amp Stabilize gain and increase frequency response
9. The voltage gain of an op-amp with external feedback Closed-loop voltage gain
10. A special case of the noninverting amplifier where all of the output voltage is fed back to the inverting input by a straight connection Voltage-follower configuration
11. The value of the frequency at which the gain steadily decreases to a point where it is equal to unity Unity-gain frequency Or unity gain bandwidth
12. It is always equal to the frequency at which the op-amp’s open- loop gain is unity or 0 dB. Gain-bandwidth product
13. The relative angular displacement of a time-varying function relative to a reference. Phase shift
14. The three terminals of the basic op-amp not including power and ground Inverting input, noninverting input, and output
15. It has the highest input impedance and the lowest output impedance of the three amplifier configurations Voltage-follower
16. The _________ of an op-amp equals the upper critical frequency. Bandwidth
17. Two types of op-amp input operation. Differential mode and common-mode
18. A ____________ differentiator uses a capacitor in series with the inverting input. Ideal 19. An ideal op-amp has ___________ value for voltage gain, bandwidth, and input impedance. Infinite
20. What should be the output voltage of an op-amp when the differential input is zero Zero
21. The ideal op-amp has __________ output impedance Zero
22. The three basic op-amp configurations Inverting, noninverting, and voltage follower
23. The closed-loop voltage gain is _________ than the open-loop voltage gain. (more or less) Less
24. Does the gain of an op-amp decreases or increases as frequency increases above the critical frequency Decreases
25. Devices such as the diode and the transistor which are separate devices that are individually packaged and interconnected in a circuit with other devices to form a complete, functional unit. Discrete components
26. Most op-amps operate with how many dc supply voltage? 2 (positive and negative)
27. Datasheets often refer to the open-loop voltage gain as the ______________ Large-signal voltage gain 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 10 AMPLIFIER FREQUENCY RESPONSE
CHAPTER 10 AMPLIFIER FREQUENCY RESPONSE
1. The frequency at which the output power drops to one-half of its midrange value Corner frequency
2. At the critical frequencies the output voltage is 70.7% of its midrange value. What is the value of voltage gain in dB? -3 dB
3. What is the other term for lower critical frequency? All of the above
4. The condition where the gain is down 3 dB is logically called _________ of the amplifier response -3 dB point
5. The upper and lower dominant critical frequencies are sometimes called
Half-power frequencies
6. A characteristic of an amplifier in which the product of the voltage gain and the bandwidth is always constant when the roll-off is -20 dB/ decade. Gain-bandwidth product
7. Critical frequencies are values of frequency at which the RC circuits reduce the voltage gain to ____________ of its midrange value. 70.7%
8. An octave of frequency change is a ________ -times change 2
9. Which of the following has no effect on the low-frequency response? Internal transistor capacitances
10. What is the gain that occurs for the range of frequencies between the lower and upper critical frequencies? Midrange gain 11. Which of the following is not a method in frequency response measurement? Roll-off measurement
12. If the voltage gain is less than one, what is the value of the dB gain? Negative
13. A plot of dB voltage gain versus frequency on semilog graph paper Bode plot
14. The critical frequency at which the curve “breaks” into a -20dB/decade drop Lower break frequency
15. The change in gain or phase shift over a specified range of input signal frequencies Frequency response
16. A unit of logarithmic gain measurement and is commonly used to express amplifier response Decibel
17. The lower and upper critical frequencies of an amplifier can be determined using the _____________ method by applying a voltage step to the input of the amplifier and measuring the rise and fall times of the resulting output voltage Step-response method
18. The coupling an bypass capacitors of an amplifier affect the _________ frequency response: high or low Low
19. The internal transistor capacitances affect the _________ frequency response: high or low High
20. Two frequency response measurement Frequency/amplitude and step
21. The Miller input and output capacitances for a BJT inverting amplifier depends on Voltage gain
22. When dB is negative, it is usually called_______ Attenuation 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
Friday, September 23, 2011
CHAPTER 9 FET AMPLIFIERS AND SWITCHING CIRCUITS
CHAPTER 9 FET AMPLIFIERS AND SWITCHING CIRCUITS
1. An amplifier that primarily uses only MOSFETs. Class D
2. A process in which an input signal is converted to a series of pulses with widths that varies proportionally to the amplitude of the input signal. PWM
3. It removes the modulating frequency and harmonics and passes only the original signal to the output. Low-Pass Filter
4. The voltage gain of a common-drain amplifier is always Slightly less than 1
5. The load resistance connected to the drain of a common-source amplifier reduces ____________ Voltage gain
6. What is the relationship between the input resistance of a common-gate amplifier to its transconductance? They are inversely proportional
7. The efficiency of a class D amplifier approaches 100%
8. The input signal is applied to the gate and the output is taken from source Common-drain
9. A nonlinear amplifier in which the transistors are operated as switches Class D
10. A device that switches an analog signal on and off Analog switch
11. Consists of two or more analog switches that connect sample portions of their analog input signals to single output in a time sequence Analog multiplexer
12. Used in low-power digital switching circuits CMOS
13. Amplifier commonly used as frequency multiplier Class C
14. The least efficient amplifier Class A
15. An amplifier that is biased below cutoff Class c
16. A class of amplifier that operates in the linear region for only a small part of the input cycle Class C
17. In a class AB amplifier, if the VBE drops are not matched to the diode drops or if the diodes are not in thermal equilibrium with the transistors, this can result in Thermal runaway 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 7 POWER AMPLIFIERS
CHAPTER 7 POWER AMPLIFIERS
1. It is the product of Q-point current and voltage of a transistor with no signal input Power dissipation
2. The ____________ of an amplifier is the ratio of the output signal power supplied to a load to the total power from the dc supply.
Efficiency
3. Which amplifier operates in the linear region for 180 deg. Of the input cycle when biased in cutoff and is in cutoff for 180 deg? Class B
4. These amplifiers are biased to conduct for slightly more than 180 deg. Class AB
5. An amplifier that is generally used in Radio Frequency applications Class C
6. Implemented with a laser diode Current mirror
7. An amplifier that is biased below cutoff and is normally operated with resonant circuit load Class C
8. The four classes of power amplifiers are classified based on the percentage of the ____________which the amplifier operates in its ________region Input cycle, linear
9. It is the ratio of the output power to the input power Power gain
10. Product of the rms load current and the rms load voltage Output power
11. A type of class B amplifier with two transistors in which one transistor conducts for one half-cycle and the other conducts for the other half-cycle Push-pull
12. Amplifiers that are generally used in Radio Frequency Applications. Class C amplifiers
13. Another term for complementary Darlington Sziklai pair
14. An advantage of push-pull class B and class AB amplifiers over class A Efficiency
15. The Q-point is at _________ at class B operation Cutoff
16. Operates in the linear region where the output signal is an amplified replica of the input signal
Class A
17. Amplifiers that have the objective of delivering power to a load Power amplifers
18. When the Q-point is at the center of the ac load line, a maximum class ________ signal can be obtained. A
19. The maximum efficiency of capacitively coupled class A amplifier cannot be higher than 25%
20. The low efficiency of class A amplifiers limits their usefulness to small power applications that require usually less than ________. 1 W 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 6 BJT AMPLIFIERS
CHAPTER 6 BJT AMPLIFIERS
1. Amplifiers designed to handle small __________ signals are referred to as small-signal amplifiers. ac only
2. Which of the r parameters is the most important? r’e
3. Determine the ac emitter resistance that is operating with a dc emitter current of 5mA. 5.0 Ω
4. If βac=hfe, αac=? hfb
5. Which of the three amplifier configurations exhibit high voltage gain and high current gain? Common-emitter
6. An amplifier configuration which has a voltage gain of approximately 1, a high input resistance and current gain, Common-collector
7. An amplifier configuration which provides high voltage gain with a maximum current gain of 1.
Common-base
8. Which of the amplifier configurations is the most appropriate for certain applications where sources tend to have low-resistance outputs? Common-base
9. In a common-emitter amplifier, any change in input signal voltage results in Opposite change in collector signal voltage
10. The ac voltage gain is the ratio of ac output voltage at the collector to ac input voltage at the base
11. the reduction in signal voltage as it passes through a circuit attenuation
12. the overall voltage gain of the common-emitter amplifier is the product of the voltage gain from base to collector and reciprocal of the attenuation
13. Without the bypass capacitor, the CE amplifier’s emitter is no longer at ac ground. How does this affect the amplifier? It decreases the ac voltage gain
14. The measure of how well an amplifier maintains its design values over changes in temperature, Stability
15. Swamping is a method used to minimize the effect of the ____________without reducing the voltage gain to its minimum value. ac emitter resistance
16. ___________ contains two transistors. The collectors of two transistors are connected and the emitter of the first drives the base of the second. Darlington pair
17. _____________ consists of two types of transistors, npn and a pnp. Complementary Darlington
18. An amplifier configuration in which the input signal is capacitively coupled to the emitter and the output is capacitively coupled from the collector, Common-base
19. Which of the amplifier configurations is/are useful at high frequencies when impedance matching is required? Common-base
20. The power gain of a common-base amplifier is approximately equal to Voltage gain
21. BJT amplifier that produces output that are a function of the difference between two input voltages, Differential amplifier
22. Ideally, a diff-amp provides a very high gain for single-ended or differential signals and _____________ gain for common-mode signals. 0
23. Input signals are out of phase Differential amplifier
ANTENNAS…
Antennas 2/2 (C6 Past board: Excel)
CONTINUATION............
ECE Board Exam November 1999Which of the following is taken as the standard reference antenna for directive gain?Isotropic
ECE Board Exam April 1998Best description of a collinear and broadside antenna radiation patternBidirectional
ECE Board Exam November 1997Theoretical gain of a Herztian dipole1.76 dB
ECE Board Exam March 1996 it is a measure of the microwave power radiated from an antenna as a function of angular direction from the antenna axisBeamwidth
ECE Board Exam November 2000What would you employ or use to determine the performance of an aerial antenna, such as determination of propagation strength and direction?Radiation pattern
ECE Board Exam April 2000Find the approximate width of a pyramidal horn antenna that will operate at 10,000 MHz intended to have a beamwidth of 10 degrees.
ECE Board Exam April 1998What is the driven element of an antenna?The element fed by the transmission line
ECE Board Exam November 1997The reflector and director of an antenna array are considered asParasitic elements
ECE Board Exam March 1996What is the gain of four identically polarized antennas stacked one above the other and fed in phase?6 dB over the gain of one antenna
ECE Board Exam April 1998What do you mean by the outward flow of an energy from any source in the form of radio waves.Radiation
ECE Board Exam November 1997The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction.ERP
ECE Board Exam March 1996Gain of an isotropic antenna0 dB
ECE Board Exam April 1997The frequency of operation of a dipole antenna cut to length of 3.4 m.
ECE Board Exam November 2000What is the term for a numerical ratio which relates the performance of one antenna to that of another real or theoretical antenna?Antenna gain
ECE Board Exam April 2000Which of the following microwave antenna is normally used when obtaining an omni-directional radiation requirement?Bicone
ECE Board Exam April 1998Antenna which is not properly terminated.Resonant
ECE Board Exam November 1997
Width measured in degrees of a major lobe between ends of the lobe at which the relative power is one half (-3dB) its value from the peak of the lobe.Beamwidth
ECE Board Exam April 1998At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna?Maximum voltage and minimum current
ECE Board Exam November 1997Harmonic suppressor connected to an antenna.Low pass filter
ECE Board Exam November 1997Radio wave concentration in the direction of the signal emitted by a directional antennaMajor lobe radiation
ECE Board Exam November 2000What is the approximate length of a half wave dipole antenna radiating at 6450 kHz?
ECE Board Exam April 2000How does the length of the director element of a parasitic element beam antenna compare with that of the driven element?It is about 5% shorter
ECE Board Exam April 1998Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other?Yagi antenna
ECE Board Exam November 2000One of the following can be best attained by a trap antenna in radio communicationMulti frequency band operation
BLAKE…
Fiber-Optic Systems (Blake C25)
Chapter 25: Fiber-Optic Systems
TRUE/FALSE
1. Most new telephone trunk cables are fiber-optic.
ANS: T
2. Cable TV systems use fiber-optic cable.
ANS: T
3. Many data network cables are fiber-optic.
ANS: T
4. Fiber-optic cable is not practical for telephone trunk cables.
ANS: F
5. CATV uses analog modulation on fiber-optic cables.
ANS: T
6. Usually, splicing losses can be disregarded in loss-budget calculations.
ANS: F
7. The rise time of a transmitter limits its bandwidth.
ANS: T
8. RZ encoding allows twice as much pulse spreading as NRZ.
ANS: F
9. The product of bandwidth times distance describes dispersion in a multimode fiber-optic cable.
ANS: T
10. Regenerative repeaters for fiber-optic cables typically convert the light signal to an electrical signal, and then back to light.
ANS: T
11. Optical amplifiers are not suitable for digital signals.
ANS: F
12. Dispersion effects accumulate when optical amplifiers are used.
ANS: T
13. Most fiber-optic systems use TDM.
ANS: T
14. Fiber-optic cables shorter than 100 km typically do not require repeaters.
ANS: T
15. SONET operates at a base speed of 25 Mbps.
ANS: F
16. SONET solves many of the timing problems in synchronizing digital signals.
ANS: T
17. SONET is typically used on LANs.
ANS: F
18. FDDI can be used on a LAN.
ANS: T
19. Soliton pulses can travel down a fiber-optic cable with no dispersion.
ANS: T
20. TDR cannot be used on fiber-optic cables.
ANS: F
MULTIPLE CHOICE
1. FDDI stands for:a. Fiber Digital Data Interface c. Fiber Distribution Delay Interfaceb. Fiber Distributed Data Interface d. Frequency-Division Data Interface
ANS: B
2. FITL stands for:a. Fiber In The Loop c. Frequency Input to The Loopb. Fiber Input Timing Loss d. Fiber Input Timing Loop
ANS: A
3. FTTC stands for:a. Fiber Transmission Timing Constraintb. Fiber Transmission Technology Committeec. Fiber Telephone Transmission Cabled. Fiber To The Curb
ANS: D
4. SONET stands for:a. Simple Optical Network c. Synchronous Optical Networkb. Standard Optical Network d. none of the above
ANS: C
5. DWDM stands for:a. Digital Wavelength-Division Modulationb. Dense Wavelength-Division Modulationc. Double Wavelength-Division Modulationd. Dense Wavelength-Division Multiplexing
ANS: D
6. A Soliton is a:a. defect in the glass c. type of pulseb. type of particle d. type of optical network
ANS: C
7. Adding bits to synchronize one digital signal to another is called:a. bit stuffing c. SDHb. bit-synch d. WDM
ANS: A
8. Power above the minimum required by an optical receiver is called:a. gain margin c. excess gainb. system margin d. overdrive
ANS: B
9. Typically, repeaters are not required for fiber-optic cable lengths up to:a. 1000 miles c. 100 kmb. 100 miles d. 10 km
ANS: C
10. In SONET, OC-1 stands for:a. Optical Carrier level one c. Optical Channel oneb. Optical Coupler unidirectional d. Optical Cable type 1
ANS: A
11. In SONET, STS stands for:a. Synchronous Transport Signal c. Synchronous Transmission Signalb. Synchronous Transport System d. Synchronous Transmission System
ANS: A
12. A commonly used fiber-based system for LANs is:a. FDDI c. gigabit Ethernetb. high-speed Ethernet d. all of the above
ANS: D
13. The use of solitons on fiber-optic cables is:a. common c. obsoleteb. experimental d. not possible
ANS: B
14. OTDR stands for:a. Optical Time-Delay Response c. Optical Time-Domain Reflectometerb. Optical Timing Delay Requirement d. Optical Time-Division Relay
ANS: C
15. Using fiber-optic cable in a telephone system except for the connection to the subscriber's phone is called:a. FDDI c. FITLb. FTTC d. SONET
ANS: B
COMPLETION
1. FTTC stands for Fiber To The ____________________.
ANS: Curb
2. FITL stands for Fiber In The ____________________.
ANS: Loop
3. SDH stands for Synchronous Data ____________________.
ANS: Hierarchy
4. WDM stands for ____________________-division multiplexing.
ANS: Wavelength
5. SONET stands for ____________________ Optical Network.
ANS: Synchronous
6. FDDI stands for Fiber ____________________ Data Interface.
ANS: Distributed
7. Optical amplifiers use ____________________-doped glass.
ANS: erbium
8. Optical amplifiers use a ____________________ laser.
ANS: pump
9. Dense ____________________ allows many different wavelengths of light to share a cable.
ANS: WDM
10. The OC-1 line rate is ____________________ Mbps.
ANS: 51.84
11. SONET does not use bit ____________________ to synchronize two digital signals.
ANS: stuffing
12. SONET uses a ____________________ to denote the starting position of an information frame.
ANS: pointer
13. FDDI systems use two ____________________ rings to carry signals.
ANS: token
14. The two rings of an FDDI system carry data in ____________________ directions.
ANS: opposite
15. Each ____________________ in an FDDI system acts as a regenerative repeater.
ANS: node
16. FDDI uses ____________________ mode cables.
ANS: multi
17. The data rate of an FDDI system is ____________________ bps.
ANS: 100 M
18. SONET frames have considerably more ____________________ than do DS frames for information about signal routing and setup.
ANS: overhead
19. The number of bytes in a SONET frame is ____________________.
ANS: 810
20. The number of bytes in the payload of a SONET frame is ____________________.
ANS: 774
21. The number of rows in a SONET frame is ____________________.
ANS: 9
22. The total number of overhead bytes in a SONET frame row is ____________________.
ANS: 4
23. The number of path overhead bytes in a SONET frame row is ____________________.
ANS: 1
24. SONET frame rows contain path overhead and ____________________ overhead.
ANS: transport
25. In SONET, SPE stands for synchronous payload ____________________.
ANS: envelope
SHORT ANSWER
1. What is the bandwidth of a first-order LPF with a rise time of 350 nanoseconds?
ANS: 1 MHz
2. Calculate the total rise time for a fiber-optic system if the transmitter, receiver, and cable each have a rise time of 50 nanoseconds.
ANS: 86.6 nanoseconds
COACHING…
Electronics Coaching notes
ELECTRONICS ENGINEERING – COACHING NOTES
Lead acid does not depend on:Ans: Rate of charge
Lead acid consists of:Ans: Dilute sulfuric acid, sponge lead, and lead peroxide
Conputer on a chip is called:Ans: Transputer
Transputer consists of
Ans: 32 bits
Nibble consists of ____ bits.Ans: 4
OP amp has a gain of approximatelyAns: 1,000,000
The voice coil has an impedance betweenAns: 4 and 100 ohms.
Semiconductor have ____ bonds.Ans: covalent
Nimak gantry robot hasAns: good precision positioning
Sulphation in a lead acid cell is Ans: to incompletely charging
Nickel cadmium can be charged or discharged becauseAns: water is neither absorbed or formed.
Daisy chainingAns: method used in determining interrupt priorities in a microcontroller.
Who coined the term robot?Ans: Karel Capek
LASER is classified asAns: monochromatic. Coherent and collimator.
555 timer consists ofAns: astable, monostable and VCO
Early effect is also calledAns: base width modulation
The effect produced due to flow of electrons and holesAns: drift current
Process of adding impurities in the intrinsic semiconductorAns: Doping
What is reduced by using bundled conduction?Ans: Power loss due to corona.
________ is also called modified Maxwell Wien bridge.Ans: Anderson bridge.
________ is a bridge that compares the capacitance of the capacitor.Ans: De Soutry bridge
It measures unkonown inductance in terms of resistance and capacitance.Ans: Anderson bridge
An IC consists of passive devices.Ans: Film IC
SI unit of luminous intesnistyAns: Candela
SI unit of illuminanceAns: Lux
A microwave diode that has a frequency range of 10-1000 GHZAns: IMPATT diode
A microwave diode in the negative resistance region.Ans: PIN diode
Schmitt trigger acts like a Ans: Latch
Fermi level is in the Ans: Forbidden gap
Invalid NAND flip-flop violationAns: S=0 C=0
Invalid NOR flip-flop violation Ans: S=1 C=1
Range of depletion width Ans: 0.5 and 1 um
Impedance matching Ans: Transformer coupling and emitter follower.
Maxwell-Wien bridge measures Ans: Inductance
D flip-flop consists ofAns: JK flip-flop, RS flip-flop and inverter
Uses binary countersAns: D flip-flop
Ideal CMRRAns: Infinity
SCARA uses ____ operationAns: Assembly
Gold doping has an advantage ofAns: Reduced storage time.
It is the time for the diode to be forward biased to off timeAns: Reverse recovery time
The reverse current doubles in every ___ °C increase in temperature. Ans: 6
LASER and LED are in what spectrum? Ans: Infrared spectrum.
GaAs is used for Ans: Infrared light or invisible light
Tapped coil oscillatorAns: Hartley
Tickler coil oscillatorAns: Armstrong
Tapped capacitor oscillatorAns: Colpitts
The sediment that allows the bottom of the lead acid cellAns: Antimony Lead alloy
Two transistors in class B is inAns: Push-pull
Photodarlington consists of Ans: Transistor and phototransistor
Largest voltage applied without irreversible damage Ans: PIV
Thermal neutron is also called _____ neutron.Ans: Slow
Avalanche breakdown is due to Ans: collision
One nibble consists ofAns: 4 bits
Large computer has a maximum of Ans: 64 bits
Card readers can read about Ans: 10.000 cards per minute
Advantage of ECLAns: Lowest propagation delay
Schottky TTL hasAns: Least propagation delay
Main advantage of CMOS Ans: Low power
CC voltage gain Ans: cannot be exceeded to unity.
Largest voltage applied without irreversible damage Ans: PIV
Transputer operates in
Ans: parallel data
It is an IC consist of passive and active devicesAns: Monolithic IC
It is an IC consist of passive devicesAns: Film
Discrete circuitAns: Digital circuit
Linear circuitAns: Analog circuit
Backhausen criterion is a condition thatAns: stops oscillating
Negative output swing occursAns: near saturation
Positive output swing occursAns: towards cut-off
When dry cell is charged,Ans: It increased in volume
Class C acts Ans: as an RF amplifier
Crystal usesAns: RF transmitter
A class of amplifier that has 85% efficiencyAns: Class C
With Si, Z=14, it isAns: Half-filled
Formation of Si in valence shellAns: 2, 8, 4
Volatile memory isAns: Semiconductor ROM
Semiconductor ROM isAns: Combinational Logic circuit
EPROM erases when strikes byAns: Ultraviolet rays
Bolometer acts like a Ans: Thermistor
Ondograph isAns: A waveshape of voltage and current.
Nickel iron cell consists of Ans: NiOH, powdered iron and its oxide and 21% of potassium.
CE isAns: Phase reversal
Photoconductive cell is also called Ans: photoresistive cell
The smallest of all h parameter isAns: hO
The formula of h11 isAns: V1/I1
The h parameter consists ofAns: Construction, operating point and temperature
Moving coil occurs inAns: DC
VTVM internal resistance is Ans: the highest internal resistance
It measures magnetic properties of ferromagneticAns: Permeameter
Simple RL low pass measures -12 dB/octave, corresponds to ___ dB/decadeAns: -40
Rotational joins of the robot is called _____Ans: Revolute joints.
Straight line joints movement of the robot is called Ans: Prismatic joints
Input and output pointAns: Handshaking
RL high pass filter has a phase difference of Ans: 45 degrees
Who invented the microprocessor in 1969?Ans: Ted Hoff
Who invented the 1st IC?Ans: Jack Kilby
dI/dt of an SCR isAns: local hot spot
3 ½ display maximum readingAns: 0999
3 ½ 1 mV readingAns: 1000
Straight line method
Ans: piecewise linear method
Improper biasing of ICAns: causes distortion
One kWh of energy is equivalent toAns: 860 kcal
Junction breakdown occurs inAns: reverse bias
Ratio of Ah and Wh isAns: greater than one.
The capacity in a cell is measured inAns: Ah
In the IC, the SiO2 layer isAns: isolation
A V/I characteristic curve is Ans: Boltzman diode characteristic.
Early effect is also called Ans: base width narrowing.
Advantage of Swinburne’s test isAns: very convenient and very economical.
An IC consists of ceramic substrateAns: thin film IC
An IC consists of alumina substrateAns: thick film IC
It is the development of a traverse electric field in a solid material when it carries an electric currentAns: Hall effect
It is used when the input signal has periodically occurring intervals in which the input waveform is quiescentAns: synchronized clamping
A circuit that produces an output only when first activated by a preliminary pulseAns: sampling gate
Successive trigerring signal induces a transition regardless of the state in which binary happens to beAns: symmetrical triggering
Both carrier drift and carrier diffusion depend on ___Ans: Einstein relation
Microprogramming isAns: A technique to implement the control logic necessary to execute instructions within a processor.
It is used to measure a speed by cutting off light at a regular intervalAns: Stroboscope
Thermal runaway isAns: is an electrochemical reaction that causes a battery to heat and possibly explode.
A kind of ROM that degrades its own memory contents as the memory is readAns: EAROM
An inductor operates at 400 HzAns: Toroidal core
An inductor operates at 95 MHzAns: Air core
Data bus Ans: It is data lines in a system bus.
In converting intrinsic into N-type extrinsic semiconductor, which element cannot be used?Ans: Indium
Pin resistor has industrial heating inAns: Hairpin form
Any solid object has ___ degrees of freedomAns: 6
Flip-flop as a latchAns: S-C flip flop
PIN diodeAns: A microwave diode frequencies up to GHz range.
Ip/Iv of a tunnel diode is used in Ans: Computer application
Noise figure of MMIC (Monolithic Microwave Integrated Circuit)Ans: 3.5 to 6 dB
Unique advantage feature of CMOSAns: Power in a nanowatt range
Any charge in a battery when taken off the vehicleAns: Bench charge
LASCR acts like a Ans: Latch
A word hasAns: 16-bit length
A double word hasAns: 32-bit length
A company who invented the word byteAns: IBM
Degrees of freedom is the number of ______ independent movements including the end effector Ans: independent
An inductor operates at 400 Hz
Ans: Toroidal core
Percentage loss of the dc wound machineAns: 1 %
When dc voltage is removed, the clamper acts as a Ans: Rectifier
CMOS has extremelyAns: Large packing density
Solar cell has a principle of Ans: Photovoltaic cell
Sensor that detects change in resistance in extrinsic semiconductorAns: Spreading Resistance Sensor (SRS)
Reduce the stray capacitance and capacitance between bridge arm by groundingAns: Wagner Grounding
A meter sensitivity control in a test instrumentAns: Linear Taper Potentiometer
A volume control in a stereo compact disc playerAns: Logarithmic Taper Potentiometer
Faster in retrieval and storage compared to magnetic tapeAns: Magnetic Disk
It has more ripple in a bandpass and cut-off frequencyAns: Chebyshev filter
Darlington pair of transistors is _____ by Beta factor.Ans: multiplied
CCD has ___ transfer electronsAns: 6
Neutral logic Ans: Trinary logic
Totally true, totally falseAns: Fuzzy logic
Which is not a factor of capacitance?Ans: Plate thickness
Ideal input impedance of an op-ampAns: Very high
Ideal output impedance of an op-ampAns: Very low
With 100 Ω to match with higher input impedance, the configuration isAns: Common base
Optocoupler consists of an Ans: LED and phototransistor
Optoisolator consists of anAns: LED and phototransistor
Positive feedbackAns: Oscillator
Phase locked loopAns: Frequency discriminator, FM detector
Air as inductor core hasAns: Greatest efficiency
What increases noise immunity in op-amp?Ans: Hysteresis
Resisitve elementAns: Horizontal axis
Reactive elementAns: Vertical axis
Sine wave with all harmonicsAns: Square wave
It abruptly changes from 2 voltage leadsAns: Square wave
63.2 %Ans: One time constant
A sine wave oscillator, sine wave circuitAns: Crystal
Positive pulse on anode terminalAns: Turning on an SCS
3 phase rectifier that uses 6 rectifier elementAns: Gratz rectifier
What uses as marker of 100 kHz?Ans: 2 flip-flops
Feature of R-S to J-K flip-flopAns: Toggle
LC balance bridgeAns: Maxwell bridge
Operator on microwave frequencyAns: GaAs over Silicon or Germanium
J-K flip-flop frequencyAns: Divides the frequency by 2.
Small capacitance formed by twisting 2 insulated wireAns: Gimmick Capacitor
Modified Miller circuitAns: Phanastron
Converts step to ramp circuitAns: Miller circuit
Servocontrolled robots are robots within ___ mm range rather than a fraction of mm.Ans: 2
It is an electron tube which emits photoelectrons when the cathode is eliminatedAns: Phototube
It is a radiant energy absorbed by the radiant to incident energyAns: Absorptance
Inventor circuitAns: Converts dc to ac circuit
Laurence or Living stoneAns: Magnetic resonator or cyclotron
MicroporgrammingAns: Sequence of five binary codes
540 degreesAns: Phase opposition
Power efficiency of solar cellAns: 5% to 15%
Thermal detectorAns: Bolometer
Exact location of dataAns: Absolute code
Fundamental frequency in all harmonicsAns: Sawtooth wave
dV/dt of SCRAns: False trigerring
Monolithic IC usesAns: Extensive large components
MOS IC usesAns: MOSFET
A diode with no depletion regionAns: Schottky diode
LED emits light becauseAns: Electron and holes recombine
What is the difference on the input impedance of BJT and FET?Ans: A FET has high input impedance while BJT has low input impedance.
Marking of scale to accept standardAns: Calibration
Zener diode is inAns: reverse diode
The temperature coefficient of extrinsic semiconductor isAns: negative
Voltage of selenium semiconductorAns: 1 V
It is preferred to manufacture diode and temperature ratingAns: Silicon
Isotope … Ans: Abundance ratio
Electron hole pair is done byAns: Thermal energy
JFET square law device is becauseAns: its characteristic curve is parabolic
Tank circuitAns: Antiresonant
Cut-in voltage or turn on voltage currentAns: Exponentially increases
Electron beam deflected from axial to enlarge Ans: Deflection defocusing
Equal ratio bridgeAns: Heaviside Campbell bridge
Silicon oxide (SiO2) is for Ans: Insulation
APD is better than PIN diode is forAns: Speed of operation
Voltage for temperature stability of zener diodeAns: 5.6 V
3 superconducting inductor in parallel Ans: Persistor
Application of semiconductorAns: Wafer
LC circuit is used forAns: Load current
Power factor of RC is betweenAns: 0 and 1
Minimum Duty Cycle of Bust converterAns: Dmin = 1 – 2fsLc
RL
Boost converter critical inductanceAns: Lc = (1-D) 2 DR L
2fs
Buck Boost converter critical inductanceAns: Lc = (1-D) 2 R L
2fs
Buck converter critical inductanceAns: Lc = (1-D)RL
2fs
Typical CMRRAns: 100 to 10,000
Typical CMRR in dBAns: 40 to 80 dB
Accuracy of Wien bridgeAns: 0.5% - 1%
Typical value of armature resistanceAns: 0.5Ω
The saturation voltage of an op-amp is ___ smaller than the power supplyAns: 2 V
Solid grounding has a voltage belowAns: 660 V
Resistance grounding has typical voltage betweenAns: 3.3 – 11 kV
Percentage conductivity of pure annealed silver wireAns: 108.8%
Percentage conductivity of 99.5% pure goldAns: 72.6%
Percentage conductivity of 63% pure aluminumAns: 63%
Corona is maximum onAns: transmission lines
Transformer that operates on the frequency range of 20 kHz to 20 MHzAns: Carrier frequency transformer
JFET configuration for buffer amplifierAns: common drain
JFET configuration for good voltage amplificationAns: common source
JFET configuration for high frequency amplifierAns: common gate
The dc-dc converterwith unregulated input voltage and regulated output voltageAns: SMPS (Single Mode Power Supply)
Corona is due to Ans: radio interference
A transformer on the frequency of 15 kHzAns: Converter transformer
Ingredients of wet cellAns: Zinc and copper
Main ingredient of dry cellAns: Zinc container
It reduces gain to a limiting levelAns: Limiter
First transistorAns: Point contact
First fuel battery was invented by _____ in 1959.Ans: F.T. Bacon
Unlike buck and boost converter, the buck boost converter featured output voltage:Ans: opposite polarity to input.
Lattice in which the lattice points are only shown in the crystalAns: Bravais Lattice
An error due to shortcoming of instrumentsAns: Systematic error
An error that cannot be correctedAns: Random error
It is a substance where the bulk is composedAns: Element
Typical voltage of lead-acidAns: 2.1 V
What type of cell used in the emergency system?Ans: Silver-zinc cell
Microcontroller consists ofAns: Microprocessor, memory, input and output unit
Percentage of the transistor current flows in the collectorAns: 95%
SMPC operates between ON state and OFF state at a frequency ofAns: 10 kHz and 40 kHz
A camera with imaging positron effect with multiple layer of silicon detectorAns: Compton camera
NMOS is _____ than PMOSAns: 6 times
What is the diameter of the wafer used in manufacturing?
Ans: 3 to 8 inches
Standard spacing for IC chipAns: 2 um and 3 um
Advanced spacing for IC chipAns: 1 um
BCC crystal structureAns: Chromium
HPC crystal structureAns: Zinc
Another name for differential amplifierAns: Subtractor
A factor that determines the filter responseAns: Damping factor
Unity gain amplifier has ____ input impedanceAns: Extremely high
Megger is Ans: used to measure high resistance
Increasing transmitter heightAns: Decrease capacitance and inductance remains the same.
Undergrounding conductor isAns: Maximum at the conductor and minimum at the sheath
A transformer that has a frequency range from 100 Hz – 150 kHzAns: Converter transformer
Surge impedance of cableAns: 50 Ω
Ideal input impedance of op-ampAns: 50 Ω
Formula for the increase % in saturation currentAns: 2((T2-T1)/10) X 100%
Ideal noise factorAns: 0 dB
Vacant lattice site with missing atom relocated to a interstitial space with no atom.Ans: Frenkel effect
FCC packing factorAns: 0.74
Linear change of inputAns: Ramp input
Instantaneous, finite inputAns: Step input
Indicating device orientation of objectAns: Selsyn
An AC bridge that measures mutual inductanceAns: Heaviside bridge
One of the most important bridge in determining link capacitancesAns: Schering bridge
Highest dielectric strengthAns: Glass
High sensitivityAns: Permanent magnet
A transformer in laminated core reducedAns: Eddy current
An analysis used for more than one voltage sourceAns: Superposition theorem
Maximum magnitude of the output voltage from an op-amp is calledAns: Saturation voltage
A graph of amplitude versus input frequencyAns: Bode plot
Effect of recombination on depletion region Ans: Emission coefficient or ideality factor
Magnetic amplifier operates at a frequency at ____ or lessAns: 100 Hz
Most commonly used couplingAns: Transformer coupling
Typical LED voltageAns: 1.6 V
Capacitance of disc ceramic capacitorAns: 100 pF
A bypass capacitor at high frequencyAns: Ceramic capacitor
Indicating device orientation of objectAns: Selsyn
Odd parity checkerAns: XOR
Shelf life of lithium cellAns: 5 to 10 years
Negative feedbackAns: Increases bandwidth and decrease voltage gain
Alkaline cell ingredientAns: Potassium hydroxide
Advantage of NiCd over lead acidAns: Cell on NiCd can be replaced
By adding parallel circuit to the inverting amplifierAns: Inverting summing
Linear amplificationAns: Level clamper
Theory of magnetic flux in a closed system equal to zero Ans: Gauss theorem
Personal errorAns: Gross error
Advantage of magnetic disk to magnetic tapeAns: Easier to read
The maximum current can safely handleAns: Ampacity
JFET reference voltageAns: Source
Buffer amplifier gainAns: 1
AWG no. 6Ans: 0.395 Ω/1000 ft.
AWG no. 12Ans: 6350 cmil
Indicating device orientation of objectAns: Selsyn
A mass of 1.66 x 10-27 kg.Ans: Unified amu
Reciprocal of Avogadro’s numberAns: amu
Electrostatic radius of an atomAns: 10-14
Manipulator has ___ degrees of freedomAns: 3
Arrange in data arraysAns: RAM
OS memoryAns: BIOS
Voltage amplifierAns: Pre-amplifier
Latest used dataAns: Cache memory
LIFOAns: Stack memory
Minimum distance of features in a chipAns: Geometry
Number of elements not found in nature but also prepared in laboratoriesAns: 105
IC advantageAns: Reliability
Minimum to maximum rangeAns: Span
1/5 of the Wi-Fi rangeAns: Bluetooth
Temperature of Class B motorAns: 130°C
Temperature of Class F motorAns: 155°C
Pure ac voltage single frequencyAns: Single pip
Cannot be used as a permanent magnetAns: Caryon
In double’s Kelvin bridge, 1Ω to 10 uΩAns: 0.05% - 0.2%
Wien bridge oscillatorAns: f = 1/(2πRC)
Most important IEEE standard interfaceAns: IEEE 488 digital interface
Common method of coupling used in cascade amplifier stagesAns: Transformer
It is most obvious at higher frequenciesAns: Corona
Early IC packaging method used in transistorsAns: TO (Transistor Outline)
PLCC
Ans: Plastic Lead chip memory
It is used in Hi-Fi audio system to split frequencies to fed tweeter and wooferAns: Crossover network
Resistance offered by a PN junction in AC conditionsAns: Dynamic resistance
Characteristic of shared systems to avoid mixing up of print outs or programsAns: Spooling
Absorption of slow moving electrons by an interleaving matter Ans: Ramsauer effect
If a load is removed from a long transmission line, the sending voltage end is less than receiving endAns: Ferranti effect
Corona results inAns: Radio interference
Ratio of thermal conductivity to electrical conductivity is directly proportional to the absolute temperature of all metalsAns: Weidemann Franz Law
Color of neutral in 3-core flexible cableAns: Blue
It is neglected in short transmission line analysisAns: Shunt admittance
It is located near transformerAns: Lightning arrester
Volume of atom ratio to cell volumeAns: Packing factor
RLC circuit that provides undamped oscillationAns: Ringing circuit
Contact between metal and heavily doped-semiconductorAns: Ohmic contact
Comparator with hysteresisAns: Schmitt trigger
Negative electron Ans: Negatron
Input continuously increases constant outputAns: Level Clamp
Four arm AC bridge measures inductance by standard capacitance Ans: Maxwell Bridge
Shows positions of lattice pointsAns: Bravais Lattice
Measures the diameter of an atomAns: Ernest Rutherford
Ratio of the AC power supply to the plate power supplyAns: Plate efficiency
Electromechanical device that converts electrical to mechanical by attraction of iron plunger to the electromagnetAns: Solenoid
Lithium batteryAns: Microcomputer memory back-up
Protection against electric shockAns: Earthing
The heat generated melts the portion at the tip of the electrode and the base of the metalAns: Shielded Metal Arc Welding (SMAW)
Advantages of PCBAns: Eliminates bigger chassis and point to point mounting
Energy to raise the electron to another orbitAns: Excitation
It is used in high voltage and high current application for most efficient regulatorAns: Switching regulator
What refers to garaging the two adjustments of an Ac bridge together in such a way that changing one adjustment changes the other in a special way, but changing the second adjustment does not change first? Ans: Orthogonal nulling
Not common sine wave generatorAns: Multivibrator
Range of degrees of freedomAns: Work envelope
Physical bend, twist, and reachAns: Manipulator
Poor selectivityAns: Wide bandwidth
It has amplifier and feedbackAns: Electronic amplifier
Maintenance of oscillation Ans: Flywheel effect
Free electrons collidal to bound electrons causing mere current carriers Ans: Avalanche effect
Magnetic leakage due to 100% couplingAns: Electromagnetic effect
A particle resulting to an atom of an element combined to form a compoundAns: Molecule
P shell number of electronsAns: 72
Solid formed by covalent bondingAns: Crystal
The resistance in the magnetic path to the magnetic lines of forceAns: Reluctance
The flux density in an iron core when the magnetic intensity is zeroAns: Residual magnetism
When an electron rises to the conduction band a hole is created in the valence band, this called _____Ans: Electron hole pair
Operating temperature of silicon.Ans: -175 to 350°C
Highly sensitive materialAns: Permanent magnet
Smallest ripple voltageAns: Multi-section LC filter
Highest torqueAns: Series motors
Motivating input in a control system which is independent with the outputAns: Command input
Development process of a microcrystal moltenAns: Crystal growth
The voltage regulator, the component used as a comparator Ans: Op-amp
It is not an resistance weldingAns: Arc welding
Atom to atom bond on surface with oxide free surfaceAns: Pressure welding
Elimination of stray capacitanceAns: Shielding and grounding
2 identical shunt motorAns: Hopkinson
In double’s Kelvin bridge, 1Ω to 10 uΩAns: 0.05% - 0.2%
AC voltage frequency converter from one form to anotherAns: Cyclo converter
Skin effect seen atAns: High frequencies
Indicates the address of next instructionAns: Program counter
Drift current is directly proportional to mobility, diffusion is directly proportional to concentration of diffusionAns: Einstein relation
dV/dt in SCRAns: False trigerring
It divides an HF signal so that a low frequency counter would be able to display the operating frequencyAns: Prescaler circuit
Responds to the variation in incident photonAns: Quantum detector
Draws less current from circuit under testAns: FETVM
It provides very high electrical isolation between control ckt and power ckt, has high impedance between light source and phototransistor.Ans: Optoisolator
It is used to measure variations by the changing metallic resistanceAns: Bolometer
Most common bolometric deviceAns: Thermistor
These are mostly used in robot than AC because it can with stand large overload.Ans: DC motor and stepper motor
Converting sine wave to series of pulsesAns: Timing Marker Generator
Current regulator aloneAns: Regulator IC alone
What do you call a short circuit having minimum resistance?Ans: Dead short
What is used in measuring wires from number 0 to number 36?Ans: AWG
Discharge of electricity from a conductor with a high potentialAns: Corona
Power transformer normally operates at ____ alternating current.Ans: 60 or 400 Hz
What probable effect on the human body if subjected to a current of 0 to 1 mA, 60 Hz, AC or 0 to 4 mA DC?Ans: Perception
What probable effect on the human body if subjected to a current of 1 to 4mA, 60 Hz, AC or 4 to 15 mA DC?Ans: Surprise
What probable effect on the human body if subjected to a current of 4 to 21 mA, 60 Hz, AC or 15 to 80 mA DC?Ans: Reflex action
What probable effect on the human body if subjected to a current of 21 to 40 mA, 60 Hz, AC or 80 to 160 mA DC?Ans: Muscular Inhibition
What probable effect on the human body if subjected to a current of 40 to 100 mA, 60 Hz, AC or 160 to 300 mA DC?Ans: Respiratory failure
What probable effect on the human body if subjected to a current of over 100 mA, 60 Hz, AC or 300 mA DC?Ans: Fatal
What is the effect of hydrogen surrounding the anode of a cell which increases the internal resistance of the cell?Ans: Polarization
What is the anode of a lead –acid cell?Ans: Lead peroxide
What is the cathode of a lead acid cell?Ans: Sponge lead
What is the anode of a NiCad Cell ?Ans: Hydroxide
What is the anode of a silver zinc cell?Ans: Silver oxide
What is the cathode of a silver zinc cell ?Ans: Zinc
What is the production of the hydrogen gas caused by a portion of the charge current breaking down the water in the electrolyte?Ans: Gassing
What is the shelf life of lithium organic cell and lithium inorganic cell?Ans: 20 years
In what charge is the charging rate determined by the battery voltage rather than a definite current value?Ans: Floating charge
What charge is used to keep a battery at full charge while the battery is idle or light duty?Ans: Floating charge
Floating charge is sometimes referred to as ___ and is accomplished with low current.Ans: Trickle charge
What is used when a battery must be recharged in the shortest possible time?Ans: Fast charge
Electrical safety precatutions must be observed. A fatal shock can occur from ___ ampere of current.Ans: 0.1
Voltages as low as ___ volts have been recorded as causing sufficient current to be fatal.Ans: 30
What type of extinguishers are used to extinguish electrical fires?Ans: CO2
Under favorable conditions, the body resistance may be as low as ___ ohmsAns: 300
The body resistance is possibly as low as ___ from temple to temple if the skin is broken.Ans: 100
In a voltage divider, bleeder current is usually determined by the ___ percent rule of thumb.Ans: 10
A theory of magnetism based upon the electron-spin principle.Ans: Domain Theory.
What action results in the increase in current that generates more heat and the cycle repeats itself until the diode draws excessive current?Ans: Thermal runaway
What is the faithful reproduction of a signal in an amplifier?Ans: Fidelity
What dc generators are designed to act as high gain amplifier?Ans: Amplidynes
What is the range of the dc resistance of most motor armatures?Ans: 0.05 to 0.5 ohms
What is usually the lamination thickness of the armature core of a small generator?Ans: 1/64 inches
Mechanical rotation of frequency is measured using a device called___.Ans: Tachometer
The rotation of frequency of recording devices and teletypewriter motors can be measured by the use of _____.Ans: Stroboscope.
What is an instrument that allows you to view rotating or reciprocating objects intermittently and produces the optical effect of a slowing down or stopping motion?Ans: Stroboscope
What is an electronic flash device in which the flash duration is very short, a few millionths of a second and can measure very rapid motion?Ans: Strobotac
What is a combination of watch and revolution counter?Ans: Chronometric tachometer
What type of bolometer is characterized as an increase in resistance as the dissipated power rises?Ans: Barreter
What type of bolometer is characterized by decrease in resistance as the power increases?Ans: Thermistor
What instrument is used for measuring radio frequency (rf) power?Ans: Thermocouple ammeter
Which of the following robots is used for machining processes?Ans: Cincinatti T3
Kuka spot welding has ___ degrees of freedom.Ans: 6
Exx1xAns: All positions
Exx2x
Ans: horizontal positions
Magnetic audio tapeAns: Parallel
Magnetic video tapeAns: Diagonal
Thickness of magnetic audio tape Ans: 1 mil
A sawtooth wave has a ____ added to become trapezoidal wave.Ans: resistor
Absent of current weldingAns: cool sub-interval
1.5 HAns: Air pot core
Who coined the term robotics?Ans: Isaac Asimov
Oldest weldingAns: Forge welding
KlystronAns: High achievable power output
Inert gasAns: MIG
Active gasAns: MAG
Antrophomorphic robot isAns: more maneuverable
It is also known as metal inert gas.Ans: Gas Metal Arc Welding (GMAW)
Robot with facial expressionAns: Kismet
Toy dinosaur robotAns: Pleo
Snap acting switchAns: Microswitch
Approach in which introduce factory automation technologyAns: Islands of automation
Degree of automatic.Ans: Level of automation
Orange, blue and gray diodeAns: IN368
It is the welding electrode comes forward and engage the metal pressing against the surface.Ans: squeeze interval
It is the welding in which the welding transformer energized and the current flows and create a weld.Ans: weld interval
It is the weld interval that is finishedAns: hold interval
Welding electrode is retractedAns: release interval
A time after release interval to the next start sequence.Ans: Standby interval.
It is a closed loop feedback control system in which one or more of the system signals represent mechanical motion.Ans: Servomechanism.
Exx3xAns: Flat
E60xx has a tensile strength of ___Ans: 60,000 psi
With AC or DC similar to E6010Ans: E6011
Major power supply of MIGAns: DCRP
Medium penetration Ans: E6013
Can be prevented by arc weldingAns: Arc flow
Faying surfaces in one spotAns: Resistance spot welding
Faying surfacesAns: Resistance seam welding
Resistance of the workAns: Resistance welding
Mass of 60-lb IR robotAns: 60 kg
Deep penetrationAns: Submerged arc
Deep penetrationAns: DC reverse
Medium penetration Ans: DC straight
Fast weldingAns: Flash welding
10,000 to 50,000 Hz weldingAns: High frequency welding
Image resolution Ans: Dot pitch
Voltage of dry electrolytic capacitorAns: 500 V
Apply electrostatic voltage in plastic Ans: Electroactive polymer
In electrolytic positive, ___ of the total heat.Ans: 2/3
Prevents coronaAns: Braid
450°F below…Ans: Soldering
above 450°F joining of two metalsAns: Brazing
Metal active gasAns: CO2
Multimeter on the lower center switchAns: Range switch
Multimeter on the lower left switchAns: Function switch
Aluminum D-ARsonval movementAns: Bobbin
Positive leadAns: Red
Negative leadAns: Black
Angular momentum of robotAns: Yaw
GaAs disadvantage Ans: more expensive
Disadvantage of Transformer to capacitive couplingAns: more expensive
A motor or transducer that converts energy (electrical, hydraulic, or pneumatic) into power used to produce motion or power. Ans: actuator
The ability of a robot to position its end effector at a programmed location in space.Ans: accuracy
Control signals that are processed by directly measuring quantities (voltages, resistances or rotation). This can be hydraulic, electronic or pneumatic. Ans: analog control
A robot or machine that resembles a human. Ans: android
A robot with rotary joints that can move much like a person’s arm. Ans: anthrophomorphic robot
An interconnected set of links and powered joints comprising a manipulator that supports or moves a wrist, hand or end effector. Ans: arm
The ability of a machine system to perceived anticipated or unanticipated new conditions, decide what actions must be performed under the conditions and plan the actions accordingly. The main areas of applications are expert systems and computer vision.Ans: artificial intelligence
Also known as assembly cell or assembly station. A concentrated group of equipment such as manipulators, vision modules, parts presenters, and support tables that are dedicated to compute assembly operations at one physical location.Ans: assembly
The use of any one several techniques to determine the presence or absence of features. This technique include simple mechanical probes and vision systems. Ans: automated inspection
Automatically controlled operation of an apparatus, process or system by mechanical or electronic devices that replace human observation, effort and decision. Ans: automation
A traveled path in space, usually referred to as a linear direction of travel in any of three dimensions. Ans: axis
A robot in which motions are controlled by driving each axis or degree of freedom against a mechanical limit stop. Ans: bang-bang robot
A platform or structure to which a robot arm is attached; the end of a kinematic chain of arm links and joints opposite to which grasps or processes external objects. Ans: base
A manufacturing unit consisting of two or more workstations or machines and the material transport mechanisms and storage buffers that interconnect them. Ans: cell
A manufacturing unit consisting of two or more cells, and the material transport mechanisms and storage buffers that interconnect them. Ans: center
An assembly between two closely related rigid members enabling on member to rotate in relation to the other around a mobile axis.Ans: complex joint
The use of an interactive terminal workstation usually with graphics capability to automate the design of products. It includes functions such as drafting and fit-up parts.Ans: computer aided design (CAD)
Working from a product design likely to exist in a CAD data base, it encompases the computer based technologies that physically produce the product, including parts program preparation, process planning, tool design, process analysis and parts processing by numerically controlled machines. Ans: computer-aided manufacturing (CAM)
A numerical control system with a dictated mini or micro computer that performs the functions of data processing and control. Ans: computerized numerical control (CNC)
The unit of automatic work for a robot. Within a cycle, subelements called trajectories define lesser but integral elements. Each trajectory is made up of points where the robot performs an operation or passes through depending upon the programming.Ans: cycle (program)
The number of independent ways the end effector can move. It is defined by the number of rotational or translational axes through which motion can be obtained.Ans: degrees of freedom
The joint that connects the upper arm and forearm on a robot. Ans: elbow
Also known as end of arm tooling or simply a hand. The subsystem that links the mechanical portion of the robot (manipulator) to the part being handled or work on, and gives the robot the ability to pick yp and transfer parts and/or handle a multitude of different tools to perform work on parts. Ans: end effector
Robots with little if any computer power. Their only intelligent functions consist of learning a sequence of manipulative actions, choreographed by a human operator using a teach box. Ans: first generation robot system
Also known as nonservo robot or open robot. A robot with stoppoint control but no trajectory control.Ans: fixed stop robot
Multipurpose robots that are adaptable and capable of being redirected trained or used for new purposes.Ans: flexibility operational
An arrangement of machine tools that is capable of standing alone, interconnected by a workpiece transport system and controlled by a central computer.Ans: flexible manufacturing system (FMS)
Also known as pedestal robot. A robot with its base permanently or semi-permanently attached to the floor or bench. Such a robot is working at one location with a maximum limited work area and in many cases servicing only one machine.Ans: floor mounted robot
That portion of a jointed arm which is connected to the wrist and elbow Ans: forearm.
An overhead mounted, rectilinear robot with a minimum of three degrees of freedom and normally not exceeding six. Ans: gantry robot.
The grasping hand of a robot, which manipulates objects and tools to fulfill a given task. Ans: gripper
An approach used to introduce factory automation technology into manufacturing by selective application of automation.Ans: islands of automation.
The degree to which a process has been made automatic. Relevant to the level of automation are questions of automatic failure recovery, the variety of situations that will be automatically handled, and the conditions under which manual intervention or action by human beings is required.Ans: level of automation
An electrical switched positioned to be switched where a motion limit occurs, thereby deactivating the actuator that causes the motion. Ans: limit switch
A mechanism usually consisting of a series of segments or links, jointed or sliding to one another, for grasping or moving objects, usually in several degrees of freedom. Ans: manipulator
A method for the control of machine tool systems. A program containing all the information, in symbolic numerical form, needed for processing a workpiece is stored on a medium such as paper or magnetic tape. Ans: numerical control
Developing robot programs partially or completely without requiring the use of the robot itself. The program is loaded into the robot’s controller for subsequent automatic action of the manipulator. Ans: off-line programming
Software that controls the execution of computer programs, may provide scheduling, allocation, debugging data management, and other functions. Ans: operating systems
Also known as positioning. The consistent movement or manipulation of an object into controlled position and altitude in space. Ans: orientation
The equipment used in conjunction with the robot for a complete robotic system. This includes grippers, conveyors, parts positioners and parts or materials feeders that are needed with the robot. Ans: peripheral equipment
Also known as bend. The angular rotation of a moving body about an axis that is perpendicular to its direction of motion and in the same plane as its top side. Ans: pitch
Also known as photoelement or photosite. A digital picture or sensor element, picture is short for picture cell. Ans: pixel
The act of providing the control instructions required for a robot to perform its intended task.Ans: programming
The envelope of variance of the robot tool print position for repeated cycles under the same conditions. It is obtained from the deviation between the positions and orientations reached at the end of several similar cycles. Contrast with accuracy. Ans: repeatability
A reprogrammable, multifunctional manipulator designed to move a material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. Ans: robot
The science of designing, building and applying robots. Ans: robotics
Also known as twist. The rotational displacement of a joint around the principal axis of its motionj, particularly at the wrist.Ans: roll
A robot with a computer processes added to the robotic controller. This addition makes it possible to perform, in real time, the calculations required to control the motions of each degree of freedom in a cooperative manner to effect smooth motions of the end effector along predetermined paths. It also become possible to integrate simple sensors, such as force torque, and proximity into the robot system ,providing some degree of adaptability to the robot’s environment. Ans: second generation robot system
A controller that operates an application though a fixed sequence of events. Ans: sequencer
A robot driven by servomechanisms, that is, motors or actuators whose driving signal is a function of the difference between a commanded position and/or rate is measured actual position and/or rate.Ans: servocontrolled robot
An automatic control mechanism consisting of a motor or actuator driven by a signal that is a function of the difference between a commanded position and/or rate and measured actual position and/or rate.Ans: servomechanism
The manipulator arm linkage joint that is attached to the base. Ans: shoulder
The maximum velocity at which a manipulator joint can move; a rate imposed by saturation in the servoloop controlling the joint. Ans: slew rate
The use of two or more cameras to pinpoint the location of an object in a three dimensional space. Ans: stereo imaging
The detection by a robot though contact of touch, force, pattern slip and movement. It allows for the determination of local shape, orientation and feedback forces of a grasped workspace.Ans: tactile sensing
A robot system characterized by the incorporation of multiple computer processors, each operating asynchronously to perform specific functions. It includes a separate low level processor for each degree of freedom and a master computer supervising and coordinating these processors, as well as providing higher-level functions. Ans: third generation robot system
The orientation of a view with a video camera, in elevation. Ans: tilt
A continuous position control response to continuously changing input requirements. Ans: tracking
A movement such that all axes remain parallel to what they were. Ans: translation
The acquisition, movement thorugh space, and release of an object by a robot.Ans: transport
The portion of a jointed arm that is connected to the shoulder. Ans: upper arm
Also known as the robot operating envelope. The set of points representing the maximum extent or reach of the robot tool in a directions. Ans: work envelope
The envelope reached by the center of the interface between the wrist and the tool, using all available axis motions. Ans: workspace
A set of joints, usually rotational, between the arm and the hand or end effector, which allow the hand or end effector to be oriented relative to the workpiece. Ans: wrist
The angular displacement of a moving joint about an axis which is perpendicular to the line of motion and the top side of the body. Ans: yaw
What magnet is used in computer memory circuits? Ans: Ring magnet
What magnet is used in some meter circuits? Ans: Horseshoe magnet
“If the electrons of the atom in a material spin more in one direction than in the other, the material will become magnetized”. This refers to what theorem?Ans: The Domain theory of Magnetism
What theorem assumes that all magnetic materials are made up of magnetic molecules which, if lined up in north to south pole order, will be a magnet. If not lined up, the magnetic fields about the molecules will neutralize each other and no magnetic effect will be noted? Ans: Weber’s theory of magnetism
What do you call a short circuit having minimum resistance? Ans: Dead short
What refers to a continuation of current flow within an electrical cell when there is no external load? Ans: Local action
The amount of increase in the resistance of 1 ohm sample of the conductor per degree of temperature rise above 0°C is called what? Ans: Temperature coefficient of resistance
What do you call the resistance to current leakage through the insulation? Ans: Insulation resistance
What is the common name for enamel insulated wire? Ans: Magnet wire
What term is general one and usually applies only to the larger sizes of conductors? Ans: Cables
The process of applying thin coat of solder to materials prior to their being soldered. Ans: Tinning
The addition of atmospheric oxygen to metal to form rust, or to cause a breakdown in the internal construction of the metal. Ans: Oxidation
What refers to a continuation of current flow within an electrical cell when there is not external load? Ans: Local action
A continuous jacket of lead molded around a single conductor or multiple conductor cable.Ans: Lead sheath
What do you call the force exerted on an insulator by the voltage in a conductor?Ans: Electrostatic stress
The discharge of electricity from a conductor with a high potential.Ans: Corona
A material that removes oxides from surfaces to be joined by soldering or welding.Ans: Flux
A synthetic mixture of rosins that is flexible and used as an insulating material. Generally used as an insulator for low and medium range voltages. Ans: Thermoplastic
The capacity of a soldering iron to generate and maintain a satisfactory soldering temperature while giving up heat to the material being soldered. Ans: Thermal inertia
What is the working voltage of a dry electrolytic capacitor? Ans: 500 V
If arcing should occur between the plates of an oil filled capacitor, the oil will tend to reseal the hole caused by the arcing. Such a capacitor is referred to as ____ capacitor. Ans: self-healing
The maximum voltage that can be steadily applied to the capacitor without the capacitor breaking down (shorting) is called ____ of the capacitor. Ans: working voltage
What is meant by “local action”? Ans: Current flow in cell with no external load.
The left side of the pulse Ans: Leading edge
The right side of the pulse Ans: Trailing edge
What is the process by which an atoms gain or losses electrons?Ans: Ionization
Any group of energy levels that results from the close proximity of atoms in a solid. Ans: Energy bands
How many pulsations per revolution have the output voltage of an elementary single coil dc generator? Ans: Two
How many commutator segments are required in a two-coil generator? Ans: Four
What is the distortion of the main field due to the effects of armature current? Ans: Armature reaction
What type of prime mover requires a specially designed high speed alternator? Ans: Steam turbine
What type of rotor is used in slower speed alternators?Ans: Salient pole rotor
What type of rotor is wound in a manner to allow high-speed use without flying apart? Ans: Turbine driven type rotor
What term is used to denote the difference in speed between the rotor which is always somewhat less than the speed of the rotating field?
Ans: Slip
What mechanical device reverses armature connections in motors and generators at the proper instant so that current continues to flow only in one direction? Ans: Commutator
What motor characteristic is affected by counter emf? Ans: Speed
How is EPROM erased? Ans: with a burst of ultraviolet light
Whenever data is transferred between devices, it involves the exchange of prearranged signals. What is this process called? Ans: Handshaking
What test is used to check for opens (or to see if the circuit is complete or continuous) and is accomplished with an ohmmeter? Ans: Continuity test
What type of circuits are caused by some conducting part of the circuit making contact either directly or indirectly with the metallic structure of the ship or chassis? Ans: Ground circuits
Shunts are usually made from what alloy? Ans: Manganin
What property of shunt is desired because of the heavy currents that often flow through shunts producing heat?Ans: Zero-temperature coefficient
In D’Arsonval meter, many turns of fine wire would be used, each turn adding more effective length to the coil. The coil is wound on an aluminum frame called ___. Ans: bobbin
What is an important point to remember when you are making an accurate resistance measurement? Ans: “Zero” the meter each time you select a new range.
BJT better than FET Ans: radio receiver
Wineglass Ans: Plasma arc welding
… plasma Ans: Plasma arc welding
Slow speed Ans: Salient pole
High speed Ans: Turbine driven type rotor
Differentiation Ans: Submerged
Comparison solenoid Ans: Relay fixed core
Human arm Ans: Serial robot
Input display signal voltage Ans: Vertical deflection coil
Replacing DC motor/recently used Ans: Piezo motor
Rapid discharge of electrical energy Ans: Percussion welding
Hydrogen Electrode Ans: E7018
False Ans: Air has the concentrated magnetic field
Electron gun tube Ans: CRT
Electron field tube Ans: Electron beam
Multicavity Klystron Ans: Variable electron speed
Fuse Ans: Quick break type
Magnetic frequency increases Ans: Power output decreases
Cause of electrons due to the longitudinalAns: Magnetic field
Along a jointAns: Upset welding
Fastest memoryAns: Flash memory
Tungsten electrodeAns: TIG
Use of non-interlaced monitorAns: Fast graph
CMOS disadvantageAns: cannot handle high power
TTLAns: least susceptible to noise
E stands forAns: American Wire Electrode
Exceeding 450°F
Ans: Brazing
Not exceeding 450°FAns: Soldering
Generators usedAns: Magnetic
Battery used as Ans: chemical
Responsible of pulsating DCAns: Commutator
Low voltage high powerAns: Center tapped Full Wave
Oldest 1940 general magnetic phenomenonAns: Colding or cold contact
JointsAns: Direct Kinematics
End effector Ans: Inverse Direct Kinematics
Nothing but to memory Ans: Flag field
Unwanted connection Ans: Fault connection
Frequency synthesizer used as Ans: Divider
Output amplitude Ans: Amplitude stability
DC motor is preferred as driver in robotics because Ans: it can withstand large overload
Welding is not used direct source because Ans: it is impracticable to draw heavy currents
Atomic hydrogen is long lived because Ans: ac is used
RF power amplifier Ans: Common base
Choke Ans: passes dc but not RF
Multivibrator Ans: Common emitter or common source
Algorithm better than ZMP Ans: Dynamic balancing
One feet with smallAns: Hopping
Automatic weldingAns: 5 intervals
Control grid of a tubeAns: gate of a FET
Impedance mismatch reactance outputAns: Transformer
Laminated coreAns: reduces eddy current loss
No load loss but not electrical lossAns: Windage
Manganese Dioxide Alkaline Acid Ans: Alkaline Cell
Draws large amount of current Ans: Rheostat
Increase RL Ans: Improved Efficiency
Single coil Ans: Elementary generator
3 classifications of robot Ans: Anthrophomorphic, SCARA, and articulated
Connects arm and end effectors Ans: Wrist
____ for bones, ____ for muscle and ____for degrees of freedom. Ans: links, actuator, and joints
Early actuator Ans: Elastic nanotube
Changing of electric energy Ans: Electroactive polymer
Variable speed Ans: DC generator
Constant speed Ans: AC generator
More robot than worker Ans: Japan
Transient suppression prevents
Ans: diode failure
Tunnel diode Ans: Dr. Leo Esaki
Zener Diode Ans: Dr. Carl Zener
Varactor diode uses Ans: Frequency stability
2 terminal communicate Ans: Handshaking
Highest fidelity Ans: Class A
Portion Ans: Class AB
FET amplifier Ans: Class AB2
Medium penetration Ans: E6013
Oxy fuel arc Ans: Oxy fuel gas welding
Electrical requirement of arc welding Ans: high open circuit voltage
Horizontal oscilloscope Ans: Time/division
Joining of metals Ans: Welding
Radio using tubes Ans: Bulk and heavy
The purpose of I in PIN diode Ans: minimizes junction capacitance
1/16 to 5/16 in in diameter Ans: American Welding Society
Degrees of freedom for General purpose effectors Ans: 20
Deep penetration welding Ans: Submerge arc welding
JFET except Ans: transconductance
Pinch off voltage Ans: Transconductance is zero
Formula for IC with leakage current Ans: IC = βIB + (β+1)ICBO
IE Ans: IE = IC - ICBO
α ICQ
Ans: ICQ = βIBQ + ICEO
IEQ
Ans: IEQ = ICQ + IBQ
Increase temperature leakage current Ans: ICBO = ICBO
(T2-T1)/10
Charge of a capacitor Ans: Q = CV
Charge Ans: Q = Qo (1-e(-t/RC))
Dependent on gap Ans: Charge efficiency
NRZI means Ans: Non-return to zero invert
Pilot cell Ans: identifies the condition of the battery
More likely to occur than zener breakdown because lightl doped Ans: Avalanche breakdown
How wire Ans: measure dc and ac
Dielectric constant of mica Ans: 6
Buck boost lossless Ans: D = (V2)/(V1+V2)
Buck Ans: D = V2/V1
Op-amp filter Ans: Polysterene
TTL Ans: open circuit high level
I2L Ans: bipolar saturated logic
EAROM Ans: Degrade data if used
6 rectifying elements Ans: Gratz rectifier
Superconductivity thin film memory consisting of a superconducting inductor Ans: Permistor
Register and counters are the same because Ans: they have the same array of flip flop and gates
High Q Ans: High selectivity
2 principles of detector Ans: Rectifier and filter
Microprocessor Ans: ALU and control unit
CPUAns: ALU and control unit
Simulate Ans: Simulator
Servocontrolled robot Ans: Soft stop
Nonservo robot Ans: Hard stop
Lowest resistivity at 293 K Ans: Copper
BIG elements Ans: Trivalent
PAA elements Ans: Pentavalent
Analog preferred than digital because Ans: of measuring signal strength
Opposing torques Ans: Deflecting and restoring torques
Code that… Ans: Absolute code
Equal ripple Ans: Eliptic filter
IlluminanceAns: Lux
Ripple sharp cutoff Ans: Chebyshev filter
Adds all harmonics
Ans: Sawtooth
Odd harmonicsAns: Square
All even harmonics Ans: Push pull
The single grid of vacuum Ans: Control grid
In low frequency cutoff, amplitude decreases by ___ from midrange value Ans: 3 dB
Change in audio rangeAns: 1 dB
COMMUNICATIONS…
Fiber Optics (Chapter 11: Past Board Excel)
ECE Board Exam April 2001Which of the following refers to the relative refractive index difference of single mode fibers?0.1 - 0.3 %
ECE Board Exam November 2000A parameter of light beam that do not change the quality when it enters one medium from another.Frequency
ECE Board Exam April 2000Which of the following limits the top speed of transmitting information in fiber optic communication?Detector speed
ECE Board Exam November 1999Type of multi-channel signal transmission in the optic fiber communication that uses twisted pair coupler to transmit two signals of different wavelengths.Frequency-division multiplexing
ECE Board Exam April 1999Best applies to an optical fiber core.A higher refractive index than the cladding
ECE Board Exam November 1998How many times bigger does the bandwidth of a fiber optic multimode have over cable?100 times bigger
ECE Board Exam April 1998What law does a light travelling in an optical fiber follow?Snell's
ECE Board Exam November 1997Band of light waves, that are too short to be seen by human eye.Ultraviolet
ECE Board Exam April 1997Insertion loss of connector-type splices for a single-mode fiber cable.0.38dB
ECE Board Exam November 1996An object father from a converging lens than its focal point always has an ________ image.inverted
ECE Board Exam March 1996The dielectric material of an optical fiber surrounding the core.Cladding
ECE Board Exam April 2001An optical time domain reflectometer used in fiber optic communication is not intended to determine one of the following:Kind of multiplexing
--------------------- An optical time domain reflectometer used in fiber optic communication-------Refractive indexLoss per kilometerLength of fiber
ECE Board Exam November 2000In wire communications system using fiber optic, the packing fraction is related to one of the following statements when referred to fiber optic bundle.Ratio of the total cross-sectional area to the total cross-sectional area of the fiber bundle
ECE Board Exam April 2000Why are fiber optic cables considered less expensive compared to coaxial cables in communication system?Use of less repeaters
ECE Board Exam November 1999An optic fiber regenerator which is used in communication is consisting of a ________ to clean up and amplify digital data moving in one direction and a similar system for the opposite direction.transmitter and receiver
ECE Board Exam April 1999How do you account the effect of light intensity on the refractive index of a fiber optic?Increases
ECE Board Exam November 1998One of the following referred to as a major component of an optical time domain reflectometer.Pulse generator laser
ECE Board Exam April 1998__________ generates light beam at a specific visible frequency.Laser
ECE Board Exam November 1997The most common device used as a light detector in fiber optic communication system.APDs
ECE Board Exam April 1997A non-coherent light source for optical communications system.LED
ECE Board Exam November 1996The loss in signal power as light travels down a fiber isattenuation
ECE Board Exam March 1996It is made from semiconductor material such as aluminum-gallium-arsenide or gallium-arsenide-phosphide.Light emitting diode
ECE Board Exam April 2001How much bigger does the bandwidth of a single mode fiber optic have over the multimode fiber?20 times bigger
ECE Board Exam November 2000Which of the following refers to the bandwidth of optical fiber?1 MHz - 500 MHz
ECE Board Exam April 2000Refers to a characteristic of a multimode fiber optic.Cladding thickness is greater than the radius of the core and the diameter of the core must be much greater than the wavelength of the light to be carried.
ECE Board Exam November 1999What do you call the loss in signal power as the light travels the fiber optic?Attenuation
ECE Board Exam April 1999 One of the characteristics of a fiber optic used in order to carry light in several modes of propagation or to become a multimode fiber.Diameter of the core must be very muuch greater than the wavelength of the light to be carried.
ECE Board Exam November 1998What kind of effect is referred to a varying light producing a varying voltage output of a detector? Photovoltaic effect
ECE Board Exam April 1998Quantity that do not change when a beam of lifgt enters one medium to anotherFrequency
ECE Board Exam April 1997Type of fiber that has the highest modal dispersion.Step-index multimode
ECE Board Exam November 1997Calculate the energy of the photon of infrared light intensity at 1.55 um.
ECE Board Exam November 1996The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted is known as __________.mode
ECE Board Exam March 1996An absorption loss caused by valence electrons in the siica material from which fibers are manufactured.Ultraviolet absorption
ECE Board Exam April 2001Which of the following is not a major component of an optical time domain reflectometer used in fiber optic communication?vertical and horizontal plates
-------------------- major component of an optical time domain reflectometer used in fiber optic communication---------------------LaserBeam splitterPulse generator
ECE Board Exam November 2000Which of the following is a part of an optical time domain reflectometer?Beam splitter
ECE Board Exam April 2000This refers to a certain material which is most sensitive to light.Photoresist
ECE Board Exam November 1999Referred to as a light source of fiber optic which supplies level of 5to 7 milliwats and having a narrow spectrum of emission.Injection laser diode
ECE Board Exam April 1999Most likely, how many times would a fiber optic break in a span of thirty years?2 - 3 times
ECE Board Exam November 1998An advantage of optic fiber rejecting an induced noise signal from magnetic field or solar storm fluxImmunity to noise
ECE Board Exam April 1998Which of the following colors of light rays has the shortest wavelength?Violet
ECE Board Exam April 1997Fiber optic cable operates near ________ frequencies.800 THz
ECE Board Exam November 1997If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time?
ECE. Board Exam November 1996Proposed the used of a clad glass fiber as a dielectric waveguideBockham and Kao
ECE Board Exam November 2000ln electronic communications where fiber optic material is used, a reflectedwave is a possibility. what happen to the polarization of this reflected wavewhen compared to its original form?Shifts to 180 degrees
ECE Board Exam April 2000The effect of multimode propagation caused the rays leaving the fiber tointerfere constructively and destructively as they leave the end of the fiberthis effect is called _________.modal delay spreading
ECE Board Exam November 1999 What is the wavelength for deep violet light?500 nmeter
ECE Board Exam April 1999A device in the fiber optic that is used to attenuate the reflected signal from the polished end of the fiber which has a possibility of developing into a noise.Isolator
ECE Board Exam November 1998One of the advantages of the fiber optic which is referred to the volume of capacity of signals it can carryBandwidth
ECE Board Exam April 1998Circuit used to amplify the optical signal in fiber optics communications links.Optical repeater
ECE Board Exam November 1997A device that reduces the intensity of light in fiber optics communication systemsOptical attenuator
ECE Board Exam April 1997Lifetime of ILDs50.000 h
ECE Board Exam November 1996What is the stage of the sand becoming a silicon?Molten
ECE Board Exam November 2000One of the major limitations of a plastic fiberoptic used in communicationDue to its high losses
ECE Board Exam April 2000One of following is considered the largest source of signal power loss in theuse of fiber optic as communications medium such as due to misalignment.ConnectionECE Board Exam NOvember 1999One of the following is related to the application of solid material as a medium where light travels.medium where Ilght travels. apphcatlon of 5DHd mater-ja}; as 3Fiber optics
ECE Board Exam April 1999Which of the following is not considered as one of the causes for the loss of signal power as light travels through a fiber optic?Inter-modulation----------------causes for the loss of signal power as light travels through a fiber optic-----------------ScatteringFiber bendingAbsorption
ECE Board Exam November 1997The core of the optical fiber has _______a higher index of refraction than the cladding
ECE Board Exam November 1997Loss due to the diffraction of light when it strikes on the irregularities formedduring the manufacturing process of the fiber optics.Rayleigh scattering loss
ECE Board Exam November 1996If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time?
ECE Board Exam November 2000A phenomenon which causes the speed of light rays propagation in the fibermaterial changes, as it passes through different medium in the fiberRefraction
ECE Board Exam April 2000At what intenial does a fiber optic needs a repeater in communicationssystem?30 to 300 miles
ECE Board Eanm November 1999Referfeq to as a limit in reducing further the loss of signal passing through afiber optic caused by scattering.Rayleigh effect
ECE Board Exam April 1999These are band of light wavelengths, that are too short to be seen by the human eye.Ultraviolet
ECE Board Exam November 1998A quarter wavelength device made of crystalline calcite that changes polarization in the optic fiber communicationRetarder
ECE Board Exam April 1999At what power levels does fiber optic have when used in electronic communications?Range of micro to milliwatts
ECE Board Exam November 1998One of the following is among the types of fiber optics used in electronics communication.Semi-graded multimode
ECE Board Exam November 1998How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic?By application of antireflection coating ECE Board Exam November 1998What is the device use in used in fiber optic communication which consist of a receiver transmitter use tc clean up and amplify digital data moving in one direction and another in opposite direction? Optic regenerator
ECE Board Exam November 2000An advantage of fiber optic over co-axial cable as a result of coupling signalsfrom one to the other due to changing magnetic field in one or both.Crosstalk
ECE Board Exam April 2001What is the index of refraction of a certain substance if light travels throughthe substance at 100 meters at a time is to 140 meters to air'?
0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Fiber Optics, Past Board
Saturday, June 16, 2012
Satellite Communications (Chapter 10: Past Board Exce)
ECE Board Exam April 2001What balance the gravitational pull of the earth to allow the satellite to stay on its orbit?Centripetal force
ECE Board Exam November 2000Satellite that rotates around the earth in a low-altitude elliptical or circular pattern.Nonsynchronous satellite
ECE Board Exam April 1999In a transoceanic satellite conversation, how much is the typical delay before a reply is heard?600 ms
ECE Board Exam November 1999What are the repeaters inside communications satellite known for?Transponders
ECE Board Exam April 2000Under a circular satellite orbiy, how high is a certain satellite located above the surface of the earth if the total satellite height is 9869 miles?
ECE Board Exam November 1998 Is a kind of satellite which has a period of revolution equivalent to the period if rotation of the
earth about its axis. Geosynchronous satellite
ECE Board Exam April 1998A radio land station in the land mobile service.Base station
ECE Board Exam November 1997The use of telecommunication for automatic indicating or recording measurement at the distance from the measuring instrument.Telemetry
ECE Board Exam April 1997_______________ is the horizontal pointing angle of an antenna.Azimuth
ECE Board Exam November 1996How many satellite orbital slots are requested by the Philippine government from ITU?6
ECE Board Exam MArch 1996The point on satellite orbit, closest to the earth isperigee
ECE Board Exam April 2001A mobile service between base stations and land mobile stations or between land mobile stations.Mobile service
ECE Board Exam November 2000Which of the following refers to the basic component of a communication satellite receiver?Transponder
ECE Board Exam April 2000Determine from the following the basic technique used to stabilize a satellite.Spin
ECE Board Exam November 1999A space distance iin satellite communication from the earth, to or greater than 2,000,000 kilometers is referred to as ___________.deep space
ECE Board Exam April 1999How many satellites does the GPS system consist?24 satellites
ECE Board Exam November 1999Which point on the satellite orbit is closest to the earth?perigee
ECE Board Exam November 1998Which of the following is refers to the smallest beam of a satellite antenna's radiation pattern?spot beam
ECE Board Exam April 1998A major and basic advantage for the use of klystron.Hiigh power
ECE Board Exam November 1997Station in the mobile service not intended to be used while in motion.Land station
ECE Board Exam April 1997__________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency.LNB
ECE Board Exam November 1996Collects very weak signals from a broadcast satellite.Satellite dish
ECE Board Exam March 1996It is a spacecraft replaced in orbit around the earth carrying onboard microwave receiving and transmitting equipmentsCommunications satellite
ECE Board Exam April 2001A what apogee in an elliptical orbit must a geosynchronous satellite be initially stationed before it is finally fired into its final geostationary orbit?22,300 miles
ECE Board Exam November 2000Satellite orbit around the earth are either:they are either circular or elliptical
ECE Board Exam April 2000Satellite system or part of a satellite system, consisting of only one satellite and the cooperating stations.Satellite network
ECE Board Exam November 1999A resultant effect in launching a satellite from the earth caused by both forward motion away
from the earth that provides inertia tending the satellite to travel in straight line upwards and the gravitational pull towards the earth is referred to as ___________.centripetal acceleration
ECE Board Exam November 1998Which of the following refers to the first active satellite?Sputnik 1
ECE Board Exam April 1998A band where most military satellite often operate.X
ECE Board Exam November1997Known to be the first satellite capable to receive and transmit simultaneously.Telstar I
ECE Board Exam April 1997What kind of battery panels are used in some advanced satellites?Gallium arsenide solar panels
ECE Board Exam November 1996Satellite signal transmitted from a satellite transponder to earth's station.Downlink
ECE Board Exam November 1999In satellite communications where satellites revolve in an orbit that forms a plane passing through the center of gravity of the earth, this center is called ____________geocenter
ECE Board Exam April 1998The use of telecommunication for the transmission of signals to initiate, modify or terminate functions of equivalent at a distance.Telecommand
ECE Board Exam November 1997The use of telecommunication for the transmission of signals to initiate modify or terminate functions of equipment at a distance.Telecommand
ECE Board Exam April 1997Footprint refers to coverage area in the globe.Satellite coverage
ECE Board Exam November 1996The first commercial satelliteEarly bird
ECE Board Exam November 1996What band does VSAT first operate?C-band
ECE Board Exam April 2001Which part of transponder converts the received signal to another lower frequency?Mixer
ECE Board Exam April 1998In satellite communications, the geostationary satellites are conveniently located with respect to the equator at __________.0 degrees latitude
ECE Board Exam November 1997The Ku-band in the satellite service.14/11 GHz
ECE Board Exam April 1997Asia Sat I covers how many countries in Asia?38
ECE Board Exam November 1996Satellite engine usesion propulsion system
ECE Board Exam April 2001How do you increase or double the channel capacity of a satellite without increasing the frequency bandwidth?Re-use frequency
ECE Board Exam April 1998A satellite beam that covers almost 42.4% of earths surface.Global beam
ECE Board Exam November 1997Receives and collects satellite signals from a broadcast satellite.Satellite disk
ECE Board Exam April 1997Sound intensity level is __________10 log I/Iref
ECE Board Exam November 1996The first passive satellite transponder.Moon
ECE Board Exam April 1998The most common application of satelliteCommunications
ECE Board Exam November 1997Radio communication operation service between mobile and land stations or between mobile stations.Mobile service
ECE Board Exam April 2001Referred to as function and/or a designed of a double conversion satellite transponder.Equipped with two mixers
ECE Board Exam November 2000How does spatial isolation technique in satellite communications avoid interference?Employment of highly directional spot-beam antennas
ECE Board Exam April 1998One of the first satellite systems catering personal based communications services scheduled for operation.Iridium system
ECE Board Exam NOvember 1997A radio communications service used in radio regulation between specified fixed points provided primarily for the safety of air navigation and for the regular efficient and economical air transport.Aeronautical Fixed Service
ECE Board Exam November 1999When do you consider that there is a satellite pass, having reference from the ground?When satellite passes at its orbit at 90 degrees from its azimuth.
ECE Board Exam April 1998Station located on an object which is beyond and is intended to go beyond the major portion of the earths athmospehere.Space Station
ECE Board Exam November 1997An earth satellite whose period of revolution is equal the period of rotation of the earth about its axis.Geosynchronous
ECE Board Exam April 1998Known as the satellite transmitted signal from a satellite transponder to earths station.Down link
ECE Board Exam November 1997A satellite receives an uplink frequency of __________ MHz from a ground station of 3700 MHz.
ECE Board Exam April 1998What do you call the signal booster installed on the antenna dish of satellite receiver?Low noise amplifier
ECE Board Exam November 1997Which of the following refers to the smallest beam of satellite antennas radiation pattern?Spot Beam
ECE Board Exam April 1998Referred by a radio regulation as the station in the mobile service not intended to be used while in motionLand Station
ECE Board Exam November 1997Satellite system or part of a satellite system, consisting of only one satellite and the operating earth station.satellite network
ECE Board Exam April 2001Typical bandwidth of a communications satellite.500 MHz
ECE Board Exam November 2000An area on earth covered by a satellite radio beam.Footprint
ECE Board Exam April 1999A twenty four (24) satellite system used in modern telecommunications to determine a location(s) on the surface of the earth.GPS
ECE Board Exam April 2001Which type of satellite transponder improves the S/N ratio which demodulates the up-link signal to recover the baseband signals and use them to remodulate the downlink transmitter?Baseband
ECE Board Exam April 1998In shipboard satellite dish antenna system, azimuth is referred as the __________horizontal aiming of the antenna
ECE Board Exam November 1997Refers to a land station in a maritime mobile service.Coast station
ECE Board Exam November 1998__________ is known to be the first satellite capable of receiving and transmitting simultaneously.Telstar I
ECE Board Exam April 1998What is the frequency range of C-band?3.4 to 6.424 GHz
ECE Board Exam November 1997An area on the surface of the earth within the boresight of the steerable satellite beam intended to be pointed.Effective boresight area
ECE Board Exam April 1998What is the approximate percentage of earth's coverage of a geostationary satellite at zero degree elevation?42.5 %
ECE Board Exam April 2001One of the following devices in satellite transponder serves as output of the receive antenna.low noise amplifier
ECE Board Exam November 2000In a re-use frequency technique of increasing satellite channel capacity of corresponding transponders, how do you control the antenna used to prevent interference?High directional antenna
ECE Board Exam November 2000Refers to a mobile earth station in the mobile-satellite service located on board shipShip earth station
ECE Board Exam April 2001A technique in satellite communications which uses a highly directional spot-beam antenna to prevent interference from frequency sharing.Frequency re-use technique
ECE Board Exam November 2000How do you determine the satellite location in latitude and longitude measurement?Designate a point on earth directly below the satellite
ECE Board Exam November 2000A point in the satellite orbit known to be the closest location to the surface of the earth.Perigee
ECE Board Exam November 2000Which satellite transponder has the most number of mixers?Double-conversion 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Satellite
Monday, June 4, 2012
Microwave Communications (Chapter 9: Past Board Excel)
ECE Board Exam April 2001Which of the following will you avoid in the construction of a microwave station?Long horizontal runs
ECE Board Exam November 2000Radio frequency where waveguides are not used extensively.150 MHz
ECE Board Exam April 2000Term used to describe a process of approaching a desired point by directing the vehicle towards that pointHoming
ECE Board Exam November 1999A system which does not refer to a technique in reducing the propagation errors in navigational system such as multipath effectsPulse transmission
ECE Board Exam April 1999Which of the following is a navigational equipment which utilizes a ground radar system to determine the position of a plane during its approach?GCA
ECE Board Exam November 1998_____________ is referred as the difference between available power and power budget.Power margin
ECE Board Exam April 1998Space diversity transmission means transmitting and receiving on __________.two or more antennas operating on the same frequency
ECE Board Exam November 1996One of the reasons why FDM is being replaced by TDM isnoise is amplified with voice when an FDM system is used
ECE Board Exam November 1996What is the baseband frequency of standard FDM basic supergroup?312 to 552 kHz
ECE Board Exam March 1996The k-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to __________4/3
ECE Board Exam March 1996LORAN is navigational system used primarily for _________obtaining your fixed location over a large distances
ECE Board Exam April 2001What navigational system technique uses an antenna directivity to reduce an undesired multipath signals?LORAN-C
ECE Board Exam November 2000In microwave frequencies, the LOS distance is something extended through the occurrence of ____________ducting
ECE Board Exam April 2000Which of the following if not a part of the navigational radar?Duplexer------------- part of navigational radar-----------PulserDisplay unitSynchronizer
ECE Board Exam November 1999How do you account the effect of selective fading on the transmitted signal in terms of its bandwidth?more affirmative at wider bandwidth
ECE Board Exam April 1999Frequencies most affected by knife-edge refraction.
VHF and UHF
ECE Board Exam April 1998Refers to an effect of selective fading.A fading effect caused by phase difference between radio wave components of the same transmission, as experienced at the receiving station.
ECE Board Exam November 1996When the clearance above the obstruction is equal to the radii of even Fresnel zones at the point of reflection the RSLis decreased
ECE Board Exam March 1996LORAN is a navigation system used primary forobtaining fixes over large distances
ECE Board Exam November 1966When the value of k increases, the effective result is _______ of the equivalent curvatures.flattening
ECE Board Exam March 1996TACAN is a navigational aid providing _________bearing and distance indication
ECE Board Exam November 1996If Ns = 250 determine the earth radius k-factor.
ECE Board Exam March 1996A one-hop, full duplex, microwave system is in a space diversity arrangement. Determine how many receivers in all are used?2
ECE Board Exam November 1996A microwave communications system space loss calculation formula is92.4 + 20 log F + 20 log D
ECE Board Exam March 1996Radio fading resulting from obstruction losses.Log normal fading
ECE Board Exam April 1998Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna.Circulator
ECE Board Exam November 1996What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path?Frequency
ECE Board Exam November 1996What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz?
ECE Board Exam November 1996Low-power radar usesIMPATT
ECE Board Exam November 2000A component of a microwave station that samples signal traveling in one direction down to the transmission line.Directional coupler
ECE Board Exam April 2000A navigational error which is caused by reflection of obstruction close to the location of navigational aid having a normal concern on directional bearing.Site error
ECE Board Exam April 1999An aircraft deviation measured by an ILS localizer.Horizontal
ECE Board Exam April 1998Which of the following systems is not used in radio detection and ranging?Amplitude modulation
----------- systems used in radio detection and ranging----------Frequency shiftFrequency modulationPulse radar
ECE Board Exam April 1997A microwave system that requires the use of repeater.Intervening system that requires the use of repeater.Distances involved are greater
ECE Board Exam November 1996Space diversity transmission means transmitting and receiving ontwo or more antennas operating on the same frequencies
ECE Board Exam April 1997RADAR meansRadio Detection and Ranging
ECE Board Exam November 2000Which band in the radio spectrum does the radio navigational system Omega transmit?VLF
ECE Board Exam November 1998Which of the following is not a common microwave application?Mobile radio
------------- common microwave application --------------RadarData transmissionSpace communications
ECE Board Exam April 1998What do you call a circuit that controls the magnetron output?Modulator
ECE Board Exam April 1997A microwave link between the earth station and the down-town terminalTerrestrial link
ECE Board Exam November 1997Two or more antennas separated by 9 wavelengths are used.Space diversity
ECE Board Exam April 2000In radio navigation, one of the following deviations of an airplane is determined by an ILS localizer.Horizontal
ECE Board Exam April 1997The advantage of periscope antenna in microwave.Shorten waveguide link
ECE Board Exam April 2000In navigational system, one of the following indication is provided by the localizer unit of the ILS.A horizontal deviation of an airpalne from its optimum path of descent along the axis of the runway.
ECE Board Exam April 1999Referred to as the cycle time difference between the master and the slave signals to reach the
receiver in the operation of loran navigational equipment.Time delay
ECE Board Exam April 1999Which of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?Weak part
ECE Board Exam April 1999What is being measured in radar theory to complete the determination of a distance to a target or object, after a high radio frequency signal is transmitted to a target?Echo time off the object to the source
DATA COMM…
Digital and Data Comunications (C8 Past Board: Excel)
ECE Board Exam April 2001Determine from the following, the term used to described the ratio of transmission rate to its minimum bandwidth which is also used to compare the performance of one digital modulation technique to another.Information capacity
ECE Board Exam November 2000A process of exchange of predetermined codes and signals to establishe a connectionHandshake
ECE Board Exam April 2000These are rules in data communications intended for establishing data links and message interpretation.Protocols
ECE Board Exam November 1999In telecommunication, what do we call the difference in the voltage levels between a driver and a terminator?Noise Margin
ECE Board Exam April 1999A network interconnection facility, which is used to interconnect networks whose architecture are entirely different, is called _________.gateway
ECE Board Exam November 1998Main basic components of a data communications are composed of the following:Transmitter, channel and receiver
ECE Board Exam April 1998A device that connects two dissimilar networks and performs the protocol conversion.Gateway
ECE Board Exam November 1997Operating method in which the transmission is made alternately in each direction of a telecommunication channel. Half-duplex operation
ECE Board Exam April 1997Transmission sent in both directions simultaneously.Duplex
ECE Board Exam November 1996A system that performs parallel-to-serial and serial to parallel conversion of data linkDTE
ECE Board Exam March 1996A word in telegraphy consist of __________ characters plus a word space.7 and 1/2
ECE Board Exam April 2001Technique used in teleprinter terminal that utilizes chemically coated paper where characters are printed.Electro thermal printing
ECE Board Exam November 2000Bit rate of a telecommunications carrier T2.6.312 Mb/s
ECE Board Exam April 2000A process of sending data in computing technology by asking each remote computer terminal one ata a time if such a computer terminal has data to send.Polling
ECE Board Exam November 1999What do you call the definite time interval it takes to a key the slave station by the master in operating the long range navigational equipment or loran?Time delay
ECE Board Exam April 1999What does the elastic store referred to in the time division multiplex system used in fiber optic? Holding memory
ECE Board Exam April 1998_________ is more prevalent in analog signals that have sleep slopes or whose amplitudes vary rapidly. Slope overload
ECE Board Exam April 1998Is the total useful information processed or communicated over a specific amount of time.Throughput
ECE Board Exam November 1997The series of periodically recurrent pulses is modulated in amplitued by the corresponding instantaneous samples.PAM
ECE Board Exam April 1997Full duplex transmission meansTwo way simultaneous transmission
ECE Board Exam November 1996The line control unit (LCU) operates on the data in digital form.Data terminal equipment (DTE)
ECE Board Exam March 1996The number of voice band channels in a master group per CCITT standard is300
ECE Board Exam April 2001Which of the following topology is normally used in system network architecture topology providing order of structure?Bus
ECE Board Exam November 2000Which of the following is referred to the SYN character of ASCII code?16H
ECE Board Exam April 2000Why is parallel transfer method in data transmission faster that serial?Bits are transferred simultaneously
ECE Board Exam November 1999In an open architecture concept of data communication, one of the following is not a function of a control layer.Integrity of data
ECE Board Exam April 1999What is the function of the network layer in computer communications?Congestion control
ECE Board Exam April 1998Which of the following term best described the overload distortion?Peak Limiting
ECE Board Exam November 1998Which of the following refers to full duplex transmission?Two way simultaneous transmission
ECE Board Exam November 1997A digital carrier facility used to transmit a DS1 - formatted signal at 1.544 Mbps.T1
ECE Board Exam April 1997Transmission system for a multidrop network.Polling
ECE Board Exam November 1996The line control unit (LCU) operates on the data in digital form.Data terminal Equipment
ECE Board Exam March 1996The expander ina companding device provides _____________less amplification for low signal levels
ECE Board Exam April 2001How would you determine if data transmission in computers and terminals is/are done in parallel transfer?If group of bits move over several lines at the same time.
ECE Board Exam November 2000How are the variations of the transmitted photograph in terms of brightness and darkness converted into voltage variations?Through photodetector
ECE Board Exam April 2000In data transmission technology signals such as voice or radio are binary transmitted over a cable known as ____________.baseband signal
ECE Board Exam November 1999Mode of communication system where both sides of the system wait for their turn to transmit at a time?Half duplex
ECE Board Exam April 1999Why is it that almost all switching-type integrated data communication circuit are called digital?They process digital information
ECE Board Exam November 1998__________ is the method encoding audio signals used in US standard 1,544 kbits/s 24 channel PCM system.Mu-law
ECE Board Exam April 1998Which of the following described the very early standard that defines binary digits as space/mark line conditions and voltage levels?V.1
ECE Board Exam November 199712 voice channels are sampled at 8000 sampling rate and encoded into 8-bit PCM word. Determine the rate of the data stream.
ECE Board Exam April 1997Synchronous modems cost more than asynchronous modem becausethey have clock recovery circuits
ECE Board Exam November 1996Codes must beagreed upon in advance between sender and receiver.
ECE Board Exam March 1996One character or a sequence of characters forming a part, or the whole of a message with a specific meaning.code
ECE Board Exam April 2001One of the data terminal devices that was invented to replace the Morse code telegraphyTeleprinter
ECE Board Exam November 2000__________ is a group of bits that acts as a single unit of information such as a letter or numeral.Byte
ECE Board Exam April 2000
Transmission of information through a communication modem is intended to transmit digital information over which of the following types of communication medium?Analog
ECE Board Exam November 1999Which of the following refers to a network facility used to physically interconnect distinct networks in computer technology?Bridge
ECE Board Exam April 1999Communication through the use of a modem, is transmission of _______ data information in ______ medium.digital, analog
ECE Board Exam November 1998Refers to an address that identifies a server on the network and a particular document on the server.Uniform resource locator
ECE Board Exam April 1998One of the following stands for SONET acronym in telecommunication. Synchronous Optical Network
ECE Board Exam November 1997The sinusoidal carrier is pulsed so that on of the binary states is represented by a carrier while the other is represented by its absence.ASK
ECE Board Exam April 1997What equation defines the composition of an ISDN basic access line? 2B + D
ECE Board Exam November 1996Quantization noise is caused bythe approximation of the quantized signal
ECE Board Exam April 2001Referred as a modem that is capable of sending and receiving fas as well as data transmission.ARQ
ECE Board Exam November 2000An equipment in data communication which is referred to as a source of information to be transmitted at one end and the sink which receives the information at the other end.DTE
ECE Board Exam April 2000In computer communication the term RS-232C is referred to as ____________.serial interface standard
ECE Board Exam April 1999Kinds of information transfer in digital communication where the bits comprising one character are sent in sequence one at a time.Serial transmission
ECE Board Exam November 1998Who is responsible in the correctness and accuracy of transmitted information content over a data communication?The transmitter and receiver
ECE Board Exam April 1998Term for the transmission of printed pictures by radio?Facsimilie
ECE Board Exam November 1997Determine the dynamic range for a 10-bit sign magnitude code.
ECE Board Exam April 1997Modem is referred to as _________Data Communication Equipment
ECE Board Exam November 1996What is the principal difference between asynchronous and synchronous transmission?The clocking is derived from the data in synchronous transmission
ECE Board Exam March 1996What is the IBM's asynchronous data link protocol designation?83B
ECE Board Exam April 2001The term used to receive a data file from a remote computer is called __________.downloading
ECE Board Exam November 2000Which of the following best described the primary source of errors in the transmission of data over telephone networks?Crosstalk
ECE Board Exam April 2000An IT network which interconnects local area network over a broad graphical area.Wide are network
ECE Board Exam April 1999Refers to the PCM transcoder which translates voice-encoded signals between different digital formats.XCBR
ECE Board Exam November 1998How do you transmit through multiplexing, a thousand of voice channel information over a single fiber optic using one wavelength?Time division
ECE Board Exam April 1998Known as the data transfer scheme that used handshaking principle.Synchronous data transfer scheme
ECE Board Exam November 1997A coherent binary phase shift keyed BPSK transmitter operates at a bit rate of 20 Mbps with a carrier to noise ratio C/N of 8.8 dB. Find Eb/No.
ECE Board Exam April 2001Which of the following modulation technique render the amplitude of any of its sidebands dependent on the modulation index?Frequency modulated
ECE Board Exam November 2000What do you call a system having a single communication channel that is shared by all machines on a network?Broadcast system
ECE Board Exam April 2000What is the baseband frequency of standard FDM basic supergroup?312 to 552 kHz
ECE Board Exam April 1999Refers to transmission of two sets of voice signals or other information through two different wavelengths.Frequency division multiplex
ECE Board Exam November 1998Which of the following is not referred to as data equipment?Modem
ECE Board Exam April 1997What is the reason why companding is employed in PCM systems?
To protect small signals in PCM from quantizing distortion
ECE Board Exam November 1996How would one squeeze more channels of communication into TDM frames of standard length?Shorten the time delay for each channel
ECE Board Exam March 1996The standard that specifies a balanced interface cable that will operate for rates up to 10 Mbps with a span distances up to 1200 m.RS - 422A
ECE Board Exam April 2001Speed of data transmission is referred to baud rate which refers to changes in symbol per second as ________. frequency and phase changes.time
ECE Board Exam November 2000In facsimile, how are variations in picture brightness and darkness converted into voltage variations?with a photodetector
ECE Board Exam April 2000Network protocol developed by US Defense Department which permits the exchange of traffic between two stations without any prior call set-up.Internet Protocol
ECE Board Exam April 1999Type of transmitting two or more channels of voice signal or other information in fiber optic communications in a selected interval of micro or milliseconds, the data or channels being received at their own time slot.Time-division multiplexing
ECE Board Exam November 1998The conversion of digital into analog for purposes of training into telephone line is done through ______.Modem
ECE Board Exam November 1997Used for time division multiplexingPulse Modulation
ECE Board Exam April 1997What is framing?Is concerned with the boundaries between characters
ECE Board Exam November 1996When one station is degnated as master and the rest of the stations are considered slaves message handling is __________.Polling
ECE Board Exam April 2001How would you differentiate timing and framing in data transmission?Timing concerned with individuals bits while framing is to boundaries between characters.
ECE Board Exam November 2000One of the following refers to the standard procedure for asynchronous to synchronous conversion.V.14
ECE Board Exam April 2000Which of the following refers to facsimile?The transmission of printed pictures for permanent display on paper
ECE Board Exam April 1999Type of transmission in which each transmission is individually synchronized, this is normally done through the use of start and stop elements.Asynchronous transmission
ECE Board Exam November 1998In communications, the transmission of binary signals will require __________more bandwidth that analog
ECE Board Exam April 1998Detrmine from the following the basic mode of transmission system in the public data network in which data are transferred from the source to the network and from the network to the destination in the frame format.Packet Mode
ECE Board Exam November 1997The difference between the original and reconstructed signal gives rise toquantizing noise
ECE Board Exam April 1997The method of determining the bandwidth of any process system is _______.
Spectral Analysis
ECE Board Exam November 1996RS-232, RS-449, RS-530, V.24, and X.21 are examples of ________.standards for interfaces between terminals and modems
ECE Board Exam March 1996One type of pulse communications systems uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of pulse modulation is calledpulse duration modulation
ECE Board Exam April 2001What kind of recording is used in facsimile?Electrothermal recording
ECE Board Exam November 2000How would you isolate data communications faults in a basic error determination technique?Carry out loop back test
ECE Board Exam April 2000Which of the following describes its system services control point, logical units and physical units as network addressable units in a data network?System network architecture
ECE Board Exam April 1999Where does harmonics in a square wave of a simple signal transmission belong?Odd
ECE Board Exam November 1998In telecommunications when we call data communications it means the transmission of ________Computer data
ECE Board Exam April 1998These are used to connect non-ISDN equipment to ISDN line.Terminal adapters
ECE Board Exam November 1997Modulation in which no signal is present between pulses.Pulse modulation
ECE Board Exam April 1997It is a protocol use to connect the other packet switching network.X.75
ECE Board Exam November 1996What is the data rate of the ISDN BAsic access B channel?64 kbps
ECE Board Exam March 1996According to the Nyquist theorem, the sampling rate that can be used in a PCM system is _____ the highest audio frequency.
twice
ECE Board Exam April 2001_________ is one of the many electronic equipments referred to as a data terminal equipment.Computer printer
ECE Board Exam November 2000Method of a telecommunications operation where transmission can be made simultaneously in both direction of a channel.Duplex operation
ECE Board Exam April 2000What refers to breaking up the data into blocks with some bounded size?Segmentation
ECE Board Exam April 1999A device that is used to permit an equipment with non-ISDN interface to be connected to the digital network.TA
ECE Board Exam April 1997Slowest communications hardware product.Asynchronous
ECE Board Exam November 1997For a sample rate of 40 kHz, determine the maximum analog input frequency
ECE Board Exam November 1996Pulse carrier at the ratio of 8000 pulse/sec is amplitude modulated by an analog signal, this type of modulation isPAM
ECE Board Exam March 1996What is one principal difference between synchronous and asynchronous transmission?The clicking is derived from the data in synchronous transmission
ECE Board Exam April 2001This a fast computing machine with large amount of secondary storage to which other computer machine in the network have access for data storage and retrieval purposes.Mainframe
ECE Board Exam April 2000A connector that has the lowest loss at ultra high frequencyType-N connector
ECE Board Exam April 1999A data communications network desiigned to provide two-way communications between a large variety of data communications terminal equipment within a relatively small geographic area.Local area network
ECE Board Exam November 1998Is individual signal for a handshake from the DCE to the DTE in response to an active condition for the request to send a signal.Clear to send
ECE Board Exam April 1997Highest theoretical frequency that can be processed at a sampling rate (fs) without aliasing.Folding frequency
ECE Board Exam November 1996A seven-bit character can represent one of _______ possibilities.128
ECE Board Exam March 1996What is the number of pins in the RS-232C interface?25
ECE Board Exam April 1997Data is directly on transmission cable.Baseband
ECE Board Exam November 1996Digital transmission provides a higher level of signal quality than analog transmission becauserepeaters regenerate digital pulses and remove distortion.
ECE Board Exam March 1996What is the transmission rate of system for transmitting the output of a microcomputer to a line printer operating at a speed of 30 lines/minute? Assume that the line printer has 8 bits of data per character and prints out 80 characters/line.
ECE Board Exam November 1998In what form does the information of data communications is transmitted between two points?Binary form
ECE Board Exam April 1997A source code whose average word length approaches the fundamental limit set by the entropy of a discrete memoryless source.Huffman code
ECE Board Exam November 1996
A ___________ interconnects LAN having identical protocols at the physical and data link layers.Bridge
ECE Board Exam April 2001What is the system that process both digital and analog quantities?Hybrid system
ECE Board Exam March 1996Communications code is __________.agreed upon in advance between sender and receiver
ECE Board Exam April 1997Gateway can interconnect LANs that have _______ protocol and formats.totally different
ECE Board Exam November 1996An invitation from the primary to a secondary to transmit a message.Polling
ECE Board Exam March 1996Which of the following pulse modulation system is analog?PWM
ECE Board Exam April 2000In spread spectrum transmission, which type of modulation is normally often used with direct-sequence?PSK
ECE Board Exam November 1999Device that comply with the ISDN network interface and be connected directly to the digital network.TE1
ECE Board Exam April 1999Two or more LANs linked together over a wide geographical area.WAN
ECE Board Exam November 1998All bits in a character are sent and received ______ in serial port.one at a time
ECE Board Exam April 1997Steps to follow to produce PCM signal.Sampling, quantizing, and coding
ECE Board Exam November 1996The tranformer signal coding method for T1 carrier isbipolar
ECE Board Exam March 1996In ______ transmission, a unique SYN character is transmitted at the beginning of each message.synchronous
ECE Board Exam April 1997Transmission sent in both directions simultaneously.Duplex
ECE Board Exam March 1996Binary communications systems are better becausethe components are simpler, less costly and more reliable
ECE Board Exam November 1996Multiplexing scheme used by baseband transmission.TDM
ECE Board Exam March 1996The correctness and accuracy of the transmitted message content isdetermined by the sender and receiver.
ECE Board Exam November 1996Digital modulation technique used in modems.PSK
ECE Board Exam March 1996Data switching systemsimprove the efficiency of data transfer
ECE Board Exam November 1996Multiplexing in a time division multiplexer occurs based uponthe position of data within a frame
ECE Board Exam March 1996The process of assigning PCM codes to absolute magnitudes.Quantizing
ECE Board Exam November 1996Ethernet is baseband system using CSMA/CD operating at10 Mbps
ECE Board Exam March 1996Asynchronous protocol ischaracter oriented
ECE Board Exam November 1996The primary purpose of data modem is tointerface digital terminal equipment to analog communication channel
ECE Board Exam March 1996_________ is a device in data transmission to interface a data terminal equipment to an analog transmission lineModem
ECE Board Exam November 1996A quadrature signaling have ______ possible states4
ECE Board Exam November 1996Rules governing the transmission of digital informationline protocol
ECE Board Exam November 1996The standard ASCIIhas 132 characters including 32 control characters.
ECE Board Exam November 1996Basic speed rate of digital system64 kbps
DIODE…
CHAPTER 3 SPECIAL- PURPOSE DIODES
CHAPTER 3SPECIAL- PURPOSE DIODES
1. Diodes that were designed to operate in reverse breakdown Zener diode
2. A device that operates in reverse bias photodiode
3. A zener diode operating in breakdown acts as a Voltage regulator 4. A positive temperature means that the zener voltage
Increases with an increase in temperature on decreases with decrease in temperature.
5. A diode that always operates in reverse-bias and is doped to maximize the inherent capacitance of the depletion region is Laser
6. When the light-emitting diode (LED) is forward-biased, __________pass the pn junction and recombine with____________ in the _________material. Electrons, holes, p-type
7. The first visible red LEDs were produced using GaAsp
8. The normalized output of the visible red, yellow, green and blue LED peaks at __________________ (nm) respectively. 660,590,540, and 460
9. Organic LEDs and LEDs produce light through the process of __________ and ___________ respectively. Electrophophorescence and electroluminescence
10. An increase in the amount of light intensity produces an increase in Reverse current
11. A diode that can be used as a variable-resistance device controlled by light intensity. Photodiode
12. A diode that operates only with majority carriers Schottky diode
13. A diode that takes advantage of the variable forward resistance characteristic. PIN diode
14. No reverse leakage current Schottky diode
15. Diode used in VHF and fast switching applications Step- Recovery diode
16. When a PIN diode is forward-biased, it acts like a Current-controlled variable resistance
17. If a tunnel diode is placed in series with the tank circuit and biased at the center of the negative-resistance portion of its characteristic curve, a _________ will result in the output. Constant sinusoidal voltage
18. The tunnel diode is only used at VHF
19. In a varactor diode, what happens to the capacitance if the reverse-bias voltage decreases a. Increases
20. The varactor capacitance ratio is also known as a. Tuning ratio 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Diode, Electronics, Notes
CHAPTER 2 DIODE APPLICATIONS
CHAPTER 2DIODE APPLICATIONS
1. An open primary or secondary winding of a power supply transformer results in 0 V
2. The output frequency of a half-wave rectifier is _________to/of the input frequency Equal
3. What is the average value of the half-wave rectified voltage given 25 V as its peak amplitude? 7.95 V
4. The PIV rating of the bridge diodes is __________to/than that required for the center-tapped configuration. Less 5. Diode circuits used to clip off portions of signal voltages above or below certain levels, Clippers
6. The output frequency of a full-wave rectifier is ________ the input frequency Twice
7. A transformer is generally specified based on _____________rather than the turns ratio, Secondary voltage 8. The period of a full-wave rectified voltage is ____________ that of a half-wave rectified voltage Half
9. The indication of the effectiveness of the filter is called Ripple factor
10. Eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage
Filter
11. Circuit that maintains a constant dc voltage for variations in the input line voltage or in the load Regulator
12. A type of full-wave rectifier that uses two diodes connected to the secondary of a center-tapped transformer Center-tapped rectifier
13. Use clamping action to increase peak rectified voltages without the necessity of increasing the transformer’s voltage rating Voltage multipliers
14. Maximum voltage appearing across the diode in reverse bias PIV
15. Caused by the charging and discharging of the filter capacitor Ripple voltage
16. A systematic process of isolating, identifying, and correcting a fault in a circuit or system Troubleshooting
17. Allows unidirectional current through the load during the entire 360° of the input cycle Full-wave rectifier
18. Allows current through the load only during one-half of the cycle. Half-wave rectifier
19. Generally used because of the surge current that initially occur s when power is first turned on Slow-blow type fuse
20. A figure of merit used to specify the performance of a voltage regulator regulation
EDGE…
CHEM 101 (EDGE)
Electron was discovered by A.J.J. Thompson
The isotopes of an element differ in the number of Neutrons
Atoms or ions which have the same electronic configurationIsoelectronic
Which group in the periodic table is known as the alkali metals.Group 1
Which group in the periodic table is known as the halogens. Group 7
Which group in the periodic table is known as the alkaline earth metals. Group 2
Which group in the periodic table is known as the noble gases. Group 8
The components resulting from a reaction is called Products
What kind of chemical bond will form in a binary compound where the elctronegativity difference between atoms is less than 1.5Covalent bond Compounds which only contain carbon and hydrogen are called Hydrocarbon
Which of the following designation means that the amount of solute is expressed in physical mass units, i.e. grams and the amount of solution is expressed in volume units, i.e. milliliters w/v
What kind of chemical bond will form in a binary compound where the elctronegativity difference between atoms is greater than 2.0 Ionic bond
The isotope of hydrogen Protium, Tritium, Deuterium
The isotope of hydrogen with only one neutronTritium
The atoms having different atomic number but the same mass number are called Isobars
What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is less than 1.5?Covalent bond
The element which has a mass of about 9 amu is beryllium (Be), atomic number 4. What is the charge on the Be atom?Neutral
The mass of an alpha particle is how many times more than that of an electron7300
Atoms with the same number of protons but different number of neutrons are calledIsotopes
The forces that hold atoms together are calledChemical bond
An atom or group of atoms that has a net positive or negative charge is calledIon
A positive ion is called Cation
A negative ion is called Anion
The force of attraction between oppositely charged ions is calledIonic bonding
The horizontal arrangement of elements of increasing atomic number in a periodic table is called Period
The vertical arrangement of elements of in a periodic table is called Group
If the number of gas molecule is doubled in a certain volume of gas, the pressure Is doubled
A symbolic representation to emphasize the valence shell of an atom is called Electron dot diagram
For which elements does the number of electrons in their outer or valence shelll correspond to their group number Representative or main group
What is the maximum number of electrons that can fit in a “p” orbital 5
The property of liquid which describes their resistance to flow is called Viscosity
The anions and cations which are unaffected by the reaction in solution are called Spectator ions
A reaction in which heat is produced is calledExothermic
The atoms having different mass number but the same number of neutrons are called IsotonesRutherford model of an atom failed to explain The position of proton and neutrons
The concept that electrons revolve around the nucleus in specific paths called orbits or energy levels was proposed by Niels Bohr
The number of atoms present in 6.023 x 10^23 12 grams of carbon-12 is called Avogadro’s constant
An instrument that separates particles of different isotopic composition and measure their individual relative masses.Mass spectrometer
These are compounds containing water molecules loosely bound to the other components.Hydrates
If a more active element replaces a less active one in a compound, the reaction is: Replacement reactions
If a single reactant is transformed by heat or electricity into two or more products, the type of reaction is:Decomposition
The numerical value for standard pressure of any gas is:760 mm Hg
Any process of extracting the metal in a fused state is calledSmelting
Which of the following does not change with change in temperature?Mass
A device used to measure density.Hydrometer
The statement “mass is neither created nor destroyed in a chemical reaction” is known as:The law of conservation of mass
What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is greater than 2.0Ionic bond
A reaction in which heat is absorbed is called Endothermic
In redox reaction, the component supplying the electrons is called the Reductant
In redox reaction, the component receiving the electrons is called the OxidantA covalent bond formed by the combination of collinear p orbitals is also called a Sigma bond
The central part of an atom is called Nucleus
The mass of a proton is about how many times that of an electron 1837
The particles in the nucleus, namely the neutrons and the protons are collectively referred to as Nucleons
The number of orbiting electron is normally _____ the number of the protons in the nucleus of an atom Equal
The chemical formula which shows the relative number of atoms of all the elements present in a compound is called the Empirical formula
The chemical formula which shows the exact number of atoms of all the elements present in a compound is called the Molecular formula
When an atom loses an electron it forms Cation
When an atom gains an electron it forms AnionThe maximum number of electrons that the first energy level can accommodate is 2
The X-rays are discovered by W.C. Roentgen
Refers to atoms or ions, which have the same electronic configuration.Isoelectronic
Which group of the periodic table is known as the akali metals?Group I
Which group is known as the halogens?Group VII
The horizontal arrangement of elements increasing atomic number in a periodic table is called:Period
The number of protons in the nucleus of an atom is called Atomic number
The measure of the resistance of an object to a change in its state of motion is called Inertia
Refers to agreement of a particular value with the true value Precision
Refers to the degree of agreement among several measurements of the same quantity Accuracy
A property of matter often used by chemist as an “identification number” for a substance Density
Protons and neutrons can be broken down further into elementary particles called Quarks
The principle of constant composition of compound, originally called “Proust’s Law” is now known as Law of definite proportion
The mass that enters into a chemical reaction remains the unchanged as a result of the reaction. In precise form: mass is neither created nor destroyed. This is known as:The law of conservation of mass
When the same elements can form two different compounds, the ratio of masses of one of the elements in the two compounds is a small whole number relative to a given mass of the other elements. This is known as:The law of multiple proportion
The ratio of the density of the test liquid to the density of the reference liquid is called Specific gravity
How many electrons are there in a covalent bond? 2 SI unit of temperature Kelvin
The elements that a compound is composed of is present in fixed and precise proportion by mass. This is known as Law of constant composition
The mass to the nearest atomic-mass unit of an atom which contains 9 protons and 10 neutrons 19 amu
The net electric charge of any atom is 0
The tendency of atoms to attract electrons into their valence shells to form anions is described by the concept of Electron affinity
The tendency of atoms to attract electrons shared in a covalent bond is called Electronegativity
A covalent bond between atoms of identical electronegativity is called Nonpolar
A formula which describes only the number of each element in the molecule is called the Molecular formula
The formula which shows how atoms are joined together is called the Structural formula
The pairs of electrons not shared in the covalent bond are called Nonbonded electrons or lone pair
The word atom comes from the Greek word ”atomos” meaning Cannot be cut
Under normal state an atom is said to be Electrically neutral
The word electron comes from the Greek word ”elektron” meaning Amber
The word proton comes from the Greek word ”proteios” meaning Of first importance
A solid which has no crystalline structure is called Amorphous
A chemical substance which readily evaporates and readily diffuses at ordinary room temperature and pressure conditions is called Volatile
Which of the following falls under fluids Both liquid and gas
The gases that rarely take part in a chemical reaction are called Noble gases
Which type of ions, metals form when enter into a chemical reaction Positive ions
The chemical name for baking soda Sodium bicarbonate
The subatomic particle with a negative charge and mass of 9.1 x 10^ -31 kg is Electron
The subatomic particle with a positive charge of mass 1.6 x 10 -27 kg is Proton
Neutron was discovered by Chadwick
ELECTRONICS COACHING…
Electronics Coaching notes
ELECTRONICS ENGINEERING – COACHING NOTES
Lead acid does not depend on:Ans: Rate of charge
Lead acid consists of:Ans: Dilute sulfuric acid, sponge lead, and lead peroxide
Conputer on a chip is called:Ans: Transputer
Transputer consists ofAns: 32 bits
Nibble consists of ____ bits.Ans: 4
OP amp has a gain of approximatelyAns: 1,000,000
The voice coil has an impedance betweenAns: 4 and 100 ohms.
Semiconductor have ____ bonds.Ans: covalent
Nimak gantry robot hasAns: good precision positioning
Sulphation in a lead acid cell is Ans: to incompletely charging
Nickel cadmium can be charged or discharged becauseAns: water is neither absorbed or formed.
Daisy chainingAns: method used in determining interrupt priorities in a microcontroller.
Who coined the term robot?Ans: Karel Capek
LASER is classified asAns: monochromatic. Coherent and collimator.
555 timer consists ofAns: astable, monostable and VCO
Early effect is also calledAns: base width modulation
The effect produced due to flow of electrons and holesAns: drift current
Process of adding impurities in the intrinsic semiconductorAns: Doping
What is reduced by using bundled conduction?Ans: Power loss due to corona.
________ is also called modified Maxwell Wien bridge.Ans: Anderson bridge.
________ is a bridge that compares the capacitance of the capacitor.Ans: De Soutry bridge
It measures unkonown inductance in terms of resistance and capacitance.Ans: Anderson bridge
An IC consists of passive devices.Ans: Film IC
SI unit of luminous intesnistyAns: Candela
SI unit of illuminanceAns: Lux
A microwave diode that has a frequency range of 10-1000 GHZAns: IMPATT diode
A microwave diode in the negative resistance region.Ans: PIN diode
Schmitt trigger acts like a Ans: Latch
Fermi level is in the Ans: Forbidden gap
Invalid NAND flip-flop violationAns: S=0 C=0
Invalid NOR flip-flop violation Ans: S=1 C=1
Range of depletion width Ans: 0.5 and 1 um
Impedance matching Ans: Transformer coupling and emitter follower.
Maxwell-Wien bridge measures Ans: Inductance
D flip-flop consists ofAns: JK flip-flop, RS flip-flop and inverter
Uses binary countersAns: D flip-flop
Ideal CMRRAns: Infinity
SCARA uses ____ operationAns: Assembly
Gold doping has an advantage ofAns: Reduced storage time.
It is the time for the diode to be forward biased to off timeAns: Reverse recovery time
The reverse current doubles in every ___ °C increase in temperature. Ans: 6
LASER and LED are in what spectrum? Ans: Infrared spectrum.
GaAs is used for Ans: Infrared light or invisible light
Tapped coil oscillatorAns: Hartley
Tickler coil oscillatorAns: Armstrong
Tapped capacitor oscillatorAns: Colpitts
The sediment that allows the bottom of the lead acid cellAns: Antimony Lead alloy
Two transistors in class B is inAns: Push-pull
Photodarlington consists of Ans: Transistor and phototransistor
Largest voltage applied without irreversible damage Ans: PIV
Thermal neutron is also called _____ neutron.Ans: Slow
Avalanche breakdown is due to Ans: collision
One nibble consists ofAns: 4 bits
Large computer has a maximum of Ans: 64 bits
Card readers can read about Ans: 10.000 cards per minute
Advantage of ECLAns: Lowest propagation delay
Schottky TTL hasAns: Least propagation delay
Main advantage of CMOS Ans: Low power
CC voltage gain Ans: cannot be exceeded to unity.
Largest voltage applied without irreversible damage
Ans: PIV
Transputer operates in Ans: parallel data
It is an IC consist of passive and active devicesAns: Monolithic IC
It is an IC consist of passive devicesAns: Film
Discrete circuitAns: Digital circuit
Linear circuitAns: Analog circuit
Backhausen criterion is a condition thatAns: stops oscillating
Negative output swing occursAns: near saturation
Positive output swing occursAns: towards cut-off
When dry cell is charged,Ans: It increased in volume
Class C acts Ans: as an RF amplifier
Crystal usesAns: RF transmitter
A class of amplifier that has 85% efficiencyAns: Class C
With Si, Z=14, it isAns: Half-filled
Formation of Si in valence shellAns: 2, 8, 4
Volatile memory isAns: Semiconductor ROM
Semiconductor ROM isAns: Combinational Logic circuit
EPROM erases when strikes byAns: Ultraviolet rays
Bolometer acts like a Ans: Thermistor
Ondograph isAns: A waveshape of voltage and current.
Nickel iron cell consists of Ans: NiOH, powdered iron and its oxide and 21% of potassium.
CE isAns: Phase reversal
Photoconductive cell is also called Ans: photoresistive cell
The smallest of all h parameter isAns: hO
The formula of h11 isAns: V1/I1
The h parameter consists ofAns: Construction, operating point and temperature
Moving coil occurs inAns: DC
VTVM internal resistance is Ans: the highest internal resistance
It measures magnetic properties of ferromagneticAns: Permeameter
Simple RL low pass measures -12 dB/octave, corresponds to ___ dB/decadeAns: -40
Rotational joins of the robot is called _____Ans: Revolute joints.
Straight line joints movement of the robot is called Ans: Prismatic joints
Input and output pointAns: Handshaking
RL high pass filter has a phase difference of Ans: 45 degrees
Who invented the microprocessor in 1969?Ans: Ted Hoff
Who invented the 1st IC?Ans: Jack Kilby
dI/dt of an SCR isAns: local hot spot
3 ½ display maximum readingAns: 0999
3 ½ 1 mV reading
Ans: 1000
Straight line methodAns: piecewise linear method
Improper biasing of ICAns: causes distortion
One kWh of energy is equivalent toAns: 860 kcal
Junction breakdown occurs inAns: reverse bias
Ratio of Ah and Wh isAns: greater than one.
The capacity in a cell is measured inAns: Ah
In the IC, the SiO2 layer isAns: isolation
A V/I characteristic curve is Ans: Boltzman diode characteristic.
Early effect is also called Ans: base width narrowing.
Advantage of Swinburne’s test isAns: very convenient and very economical.
An IC consists of ceramic substrateAns: thin film IC
An IC consists of alumina substrateAns: thick film IC
It is the development of a traverse electric field in a solid material when it carries an electric currentAns: Hall effect
It is used when the input signal has periodically occurring intervals in which the input waveform is quiescentAns: synchronized clamping
A circuit that produces an output only when first activated by a preliminary pulseAns: sampling gate
Successive trigerring signal induces a transition regardless of the state in which binary happens to beAns: symmetrical triggering
Both carrier drift and carrier diffusion depend on ___Ans: Einstein relation
Microprogramming isAns: A technique to implement the control logic necessary to execute instructions within a processor.
It is used to measure a speed by cutting off light at a regular intervalAns: Stroboscope
Thermal runaway isAns: is an electrochemical reaction that causes a battery to heat and possibly explode.
A kind of ROM that degrades its own memory contents as the memory is readAns: EAROM
An inductor operates at 400 HzAns: Toroidal core
An inductor operates at 95 MHzAns: Air core
Data bus Ans: It is data lines in a system bus.
In converting intrinsic into N-type extrinsic semiconductor, which element cannot be used?Ans: Indium
Pin resistor has industrial heating inAns: Hairpin form
Any solid object has ___ degrees of freedomAns: 6
Flip-flop as a latchAns: S-C flip flop
PIN diodeAns: A microwave diode frequencies up to GHz range.
Ip/Iv of a tunnel diode is used in Ans: Computer application
Noise figure of MMIC (Monolithic Microwave Integrated Circuit)Ans: 3.5 to 6 dB
Unique advantage feature of CMOSAns: Power in a nanowatt range
Any charge in a battery when taken off the vehicleAns: Bench charge
LASCR acts like a Ans: Latch
A word hasAns: 16-bit length
A double word hasAns: 32-bit length
A company who invented the word byteAns: IBM
Degrees of freedom is the number of ______ independent movements including the end effector
Ans: independent
An inductor operates at 400 HzAns: Toroidal core
Percentage loss of the dc wound machineAns: 1 %
When dc voltage is removed, the clamper acts as a Ans: Rectifier
CMOS has extremelyAns: Large packing density
Solar cell has a principle of Ans: Photovoltaic cell
Sensor that detects change in resistance in extrinsic semiconductorAns: Spreading Resistance Sensor (SRS)
Reduce the stray capacitance and capacitance between bridge arm by groundingAns: Wagner Grounding
A meter sensitivity control in a test instrumentAns: Linear Taper Potentiometer
A volume control in a stereo compact disc playerAns: Logarithmic Taper Potentiometer
Faster in retrieval and storage compared to magnetic tapeAns: Magnetic Disk
It has more ripple in a bandpass and cut-off frequencyAns: Chebyshev filter
Darlington pair of transistors is _____ by Beta factor.Ans: multiplied
CCD has ___ transfer electronsAns: 6
Neutral logic Ans: Trinary logic
Totally true, totally falseAns: Fuzzy logic
Which is not a factor of capacitance?Ans: Plate thickness
Ideal input impedance of an op-ampAns: Very high
Ideal output impedance of an op-ampAns: Very low
With 100 Ω to match with higher input impedance, the configuration isAns: Common base
Optocoupler consists of an Ans: LED and phototransistor
Optoisolator consists of anAns: LED and phototransistor
Positive feedbackAns: Oscillator
Phase locked loopAns: Frequency discriminator, FM detector
Air as inductor core hasAns: Greatest efficiency
What increases noise immunity in op-amp?Ans: Hysteresis
Resisitve elementAns: Horizontal axis
Reactive elementAns: Vertical axis
Sine wave with all harmonicsAns: Square wave
It abruptly changes from 2 voltage leadsAns: Square wave
63.2 %Ans: One time constant
A sine wave oscillator, sine wave circuitAns: Crystal
Positive pulse on anode terminalAns: Turning on an SCS
3 phase rectifier that uses 6 rectifier elementAns: Gratz rectifier
What uses as marker of 100 kHz?Ans: 2 flip-flops
Feature of R-S to J-K flip-flopAns: Toggle
LC balance bridgeAns: Maxwell bridge
Operator on microwave frequencyAns: GaAs over Silicon or Germanium
J-K flip-flop frequencyAns: Divides the frequency by 2.
Small capacitance formed by twisting 2 insulated wireAns: Gimmick Capacitor
Modified Miller circuitAns: Phanastron
Converts step to ramp circuitAns: Miller circuit
Servocontrolled robots are robots within ___ mm range rather than a fraction of mm.Ans: 2
It is an electron tube which emits photoelectrons when the cathode is eliminatedAns: Phototube
It is a radiant energy absorbed by the radiant to incident energyAns: Absorptance
Inventor circuitAns: Converts dc to ac circuit
Laurence or Living stoneAns: Magnetic resonator or cyclotron
MicroporgrammingAns: Sequence of five binary codes
540 degreesAns: Phase opposition
Power efficiency of solar cellAns: 5% to 15%
Thermal detectorAns: Bolometer
Exact location of dataAns: Absolute code
Fundamental frequency in all harmonicsAns: Sawtooth wave
dV/dt of SCRAns: False trigerring
Monolithic IC usesAns: Extensive large components
MOS IC usesAns: MOSFET
A diode with no depletion regionAns: Schottky diode
LED emits light becauseAns: Electron and holes recombine
What is the difference on the input impedance of BJT and FET?Ans: A FET has high input impedance while BJT has low input impedance.
Marking of scale to accept standardAns: Calibration
Zener diode is inAns: reverse diode
The temperature coefficient of extrinsic semiconductor isAns: negative
Voltage of selenium semiconductorAns: 1 V
It is preferred to manufacture diode and temperature ratingAns: Silicon
Isotope … Ans: Abundance ratio
Electron hole pair is done byAns: Thermal energy
JFET square law device is becauseAns: its characteristic curve is parabolic
Tank circuitAns: Antiresonant
Cut-in voltage or turn on voltage currentAns: Exponentially increases
Electron beam deflected from axial to enlarge Ans: Deflection defocusing
Equal ratio bridgeAns: Heaviside Campbell bridge
Silicon oxide (SiO2) is for Ans: Insulation
APD is better than PIN diode is forAns: Speed of operation
Voltage for temperature stability of zener diodeAns: 5.6 V
3 superconducting inductor in parallel Ans: Persistor
Application of semiconductorAns: Wafer
LC circuit is used forAns: Load current
Power factor of RC is betweenAns: 0 and 1
Minimum Duty Cycle of Bust converter
Ans: Dmin = 1 – 2fsLc
RL
Boost converter critical inductanceAns: Lc = (1-D) 2 DR L
2fs
Buck Boost converter critical inductanceAns: Lc = (1-D) 2 R L
2fs
Buck converter critical inductanceAns: Lc = (1-D)RL
2fs
Typical CMRRAns: 100 to 10,000
Typical CMRR in dBAns: 40 to 80 dB
Accuracy of Wien bridgeAns: 0.5% - 1%
Typical value of armature resistanceAns: 0.5Ω
The saturation voltage of an op-amp is ___ smaller than the power supplyAns: 2 V
Solid grounding has a voltage belowAns: 660 V
Resistance grounding has typical voltage betweenAns: 3.3 – 11 kV
Percentage conductivity of pure annealed silver wireAns: 108.8%
Percentage conductivity of 99.5% pure goldAns: 72.6%
Percentage conductivity of 63% pure aluminumAns: 63%
Corona is maximum onAns: transmission lines
Transformer that operates on the frequency range of 20 kHz to 20 MHzAns: Carrier frequency transformer
JFET configuration for buffer amplifierAns: common drain
JFET configuration for good voltage amplificationAns: common source
JFET configuration for high frequency amplifierAns: common gate
The dc-dc converterwith unregulated input voltage and regulated output voltageAns: SMPS (Single Mode Power Supply)
Corona is due to Ans: radio interference
A transformer on the frequency of 15 kHzAns: Converter transformer
Ingredients of wet cellAns: Zinc and copper
Main ingredient of dry cellAns: Zinc container
It reduces gain to a limiting levelAns: Limiter
First transistorAns: Point contact
First fuel battery was invented by _____ in 1959.Ans: F.T. Bacon
Unlike buck and boost converter, the buck boost converter featured output voltage:Ans: opposite polarity to input.
Lattice in which the lattice points are only shown in the crystalAns: Bravais Lattice
An error due to shortcoming of instrumentsAns: Systematic error
An error that cannot be correctedAns: Random error
It is a substance where the bulk is composedAns: Element
Typical voltage of lead-acidAns: 2.1 V
What type of cell used in the emergency system?Ans: Silver-zinc cell
Microcontroller consists ofAns: Microprocessor, memory, input and output unit
Percentage of the transistor current flows in the collectorAns: 95%
SMPC operates between ON state and OFF state at a frequency ofAns: 10 kHz and 40 kHz
A camera with imaging positron effect with multiple layer of silicon detectorAns: Compton camera
NMOS is _____ than PMOS
Ans: 6 times
What is the diameter of the wafer used in manufacturing?Ans: 3 to 8 inches
Standard spacing for IC chipAns: 2 um and 3 um
Advanced spacing for IC chipAns: 1 um
BCC crystal structureAns: Chromium
HPC crystal structureAns: Zinc
Another name for differential amplifierAns: Subtractor
A factor that determines the filter responseAns: Damping factor
Unity gain amplifier has ____ input impedanceAns: Extremely high
Megger is Ans: used to measure high resistance
Increasing transmitter heightAns: Decrease capacitance and inductance remains the same.
Undergrounding conductor isAns: Maximum at the conductor and minimum at the sheath
A transformer that has a frequency range from 100 Hz – 150 kHzAns: Converter transformer
Surge impedance of cableAns: 50 Ω
Ideal input impedance of op-ampAns: 50 Ω
Formula for the increase % in saturation currentAns: 2((T2-T1)/10) X 100%
Ideal noise factorAns: 0 dB
Vacant lattice site with missing atom relocated to a interstitial space with no atom.Ans: Frenkel effect
FCC packing factorAns: 0.74
Linear change of inputAns: Ramp input
Instantaneous, finite inputAns: Step input
Indicating device orientation of objectAns: Selsyn
An AC bridge that measures mutual inductanceAns: Heaviside bridge
One of the most important bridge in determining link capacitancesAns: Schering bridge
Highest dielectric strengthAns: Glass
High sensitivityAns: Permanent magnet
A transformer in laminated core reducedAns: Eddy current
An analysis used for more than one voltage sourceAns: Superposition theorem
Maximum magnitude of the output voltage from an op-amp is calledAns: Saturation voltage
A graph of amplitude versus input frequencyAns: Bode plot
Effect of recombination on depletion region Ans: Emission coefficient or ideality factor
Magnetic amplifier operates at a frequency at ____ or lessAns: 100 Hz
Most commonly used couplingAns: Transformer coupling
Typical LED voltageAns: 1.6 V
Capacitance of disc ceramic capacitorAns: 100 pF
A bypass capacitor at high frequencyAns: Ceramic capacitor
Indicating device orientation of objectAns: Selsyn
Odd parity checkerAns: XOR
Shelf life of lithium cellAns: 5 to 10 years
Negative feedbackAns: Increases bandwidth and decrease voltage gain
Alkaline cell ingredientAns: Potassium hydroxide
Advantage of NiCd over lead acidAns: Cell on NiCd can be replaced
By adding parallel circuit to the inverting amplifierAns: Inverting summing
Linear amplificationAns: Level clamper
Theory of magnetic flux in a closed system equal to zero Ans: Gauss theorem
Personal errorAns: Gross error
Advantage of magnetic disk to magnetic tapeAns: Easier to read
The maximum current can safely handleAns: Ampacity
JFET reference voltageAns: Source
Buffer amplifier gainAns: 1
AWG no. 6Ans: 0.395 Ω/1000 ft.
AWG no. 12Ans: 6350 cmil
Indicating device orientation of objectAns: Selsyn
A mass of 1.66 x 10-27 kg.Ans: Unified amu
Reciprocal of Avogadro’s numberAns: amu
Electrostatic radius of an atomAns: 10-14
Manipulator has ___ degrees of freedomAns: 3
Arrange in data arraysAns: RAM
OS memoryAns: BIOS
Voltage amplifierAns: Pre-amplifier
Latest used dataAns: Cache memory
LIFOAns: Stack memory
Minimum distance of features in a chipAns: Geometry
Number of elements not found in nature but also prepared in laboratoriesAns: 105
IC advantageAns: Reliability
Minimum to maximum rangeAns: Span
1/5 of the Wi-Fi rangeAns: Bluetooth
Temperature of Class B motorAns: 130°C
Temperature of Class F motorAns: 155°C
Pure ac voltage single frequencyAns: Single pip
Cannot be used as a permanent magnetAns: Caryon
In double’s Kelvin bridge, 1Ω to 10 uΩAns: 0.05% - 0.2%
Wien bridge oscillatorAns: f = 1/(2πRC)
Most important IEEE standard interfaceAns: IEEE 488 digital interface
Common method of coupling used in cascade amplifier stagesAns: Transformer
It is most obvious at higher frequenciesAns: Corona
Early IC packaging method used in transistors
Ans: TO (Transistor Outline)
PLCCAns: Plastic Lead chip memory
It is used in Hi-Fi audio system to split frequencies to fed tweeter and wooferAns: Crossover network
Resistance offered by a PN junction in AC conditionsAns: Dynamic resistance
Characteristic of shared systems to avoid mixing up of print outs or programsAns: Spooling
Absorption of slow moving electrons by an interleaving matter Ans: Ramsauer effect
If a load is removed from a long transmission line, the sending voltage end is less than receiving endAns: Ferranti effect
Corona results inAns: Radio interference
Ratio of thermal conductivity to electrical conductivity is directly proportional to the absolute temperature of all metalsAns: Weidemann Franz Law
Color of neutral in 3-core flexible cableAns: Blue
It is neglected in short transmission line analysisAns: Shunt admittance
It is located near transformerAns: Lightning arrester
Volume of atom ratio to cell volumeAns: Packing factor
RLC circuit that provides undamped oscillationAns: Ringing circuit
Contact between metal and heavily doped-semiconductorAns: Ohmic contact
Comparator with hysteresisAns: Schmitt trigger
Negative electron Ans: Negatron
Input continuously increases constant outputAns: Level Clamp
Four arm AC bridge measures inductance by standard capacitance Ans: Maxwell Bridge
Shows positions of lattice pointsAns: Bravais Lattice
Measures the diameter of an atomAns: Ernest Rutherford
Ratio of the AC power supply to the plate power supplyAns: Plate efficiency
Electromechanical device that converts electrical to mechanical by attraction of iron plunger to the electromagnetAns: Solenoid
Lithium batteryAns: Microcomputer memory back-up
Protection against electric shockAns: Earthing
The heat generated melts the portion at the tip of the electrode and the base of the metalAns: Shielded Metal Arc Welding (SMAW)
Advantages of PCBAns: Eliminates bigger chassis and point to point mounting
Energy to raise the electron to another orbitAns: Excitation
It is used in high voltage and high current application for most efficient regulatorAns: Switching regulator
What refers to garaging the two adjustments of an Ac bridge together in such a way that changing one adjustment changes the other in a special way, but changing the second adjustment does not change first? Ans: Orthogonal nulling
Not common sine wave generatorAns: Multivibrator
Range of degrees of freedomAns: Work envelope
Physical bend, twist, and reachAns: Manipulator
Poor selectivityAns: Wide bandwidth
It has amplifier and feedbackAns: Electronic amplifier
Maintenance of oscillation Ans: Flywheel effect
Free electrons collidal to bound electrons causing mere current carriers Ans: Avalanche effect
Magnetic leakage due to 100% couplingAns: Electromagnetic effect
A particle resulting to an atom of an element combined to form a compoundAns: Molecule
P shell number of electronsAns: 72
Solid formed by covalent bondingAns: Crystal
The resistance in the magnetic path to the magnetic lines of forceAns: Reluctance
The flux density in an iron core when the magnetic intensity is zeroAns: Residual magnetism
When an electron rises to the conduction band a hole is created in the valence band, this called _____Ans: Electron hole pair
Operating temperature of silicon.Ans: -175 to 350°C
Highly sensitive materialAns: Permanent magnet
Smallest ripple voltageAns: Multi-section LC filter
Highest torqueAns: Series motors
Motivating input in a control system which is independent with the outputAns: Command input
Development process of a microcrystal moltenAns: Crystal growth
The voltage regulator, the component used as a comparator Ans: Op-amp
It is not an resistance weldingAns: Arc welding
Atom to atom bond on surface with oxide free surfaceAns: Pressure welding
Elimination of stray capacitanceAns: Shielding and grounding
2 identical shunt motorAns: Hopkinson
In double’s Kelvin bridge, 1Ω to 10 uΩAns: 0.05% - 0.2%
AC voltage frequency converter from one form to anotherAns: Cyclo converter
Skin effect seen atAns: High frequencies
Indicates the address of next instructionAns: Program counter
Drift current is directly proportional to mobility, diffusion is directly proportional to concentration of diffusionAns: Einstein relation
dV/dt in SCRAns: False trigerring
It divides an HF signal so that a low frequency counter would be able to display the operating frequencyAns: Prescaler circuit
Responds to the variation in incident photonAns: Quantum detector
Draws less current from circuit under testAns: FETVM
It provides very high electrical isolation between control ckt and power ckt, has high impedance between light source and phototransistor.Ans: Optoisolator
It is used to measure variations by the changing metallic resistanceAns: Bolometer
Most common bolometric deviceAns: Thermistor
These are mostly used in robot than AC because it can with stand large overload.Ans: DC motor and stepper motor
Converting sine wave to series of pulsesAns: Timing Marker Generator
Current regulator aloneAns: Regulator IC alone
What do you call a short circuit having minimum resistance?Ans: Dead short
What is used in measuring wires from number 0 to number 36?Ans: AWG
Discharge of electricity from a conductor with a high potentialAns: Corona
Power transformer normally operates at ____ alternating current.Ans: 60 or 400 Hz
What probable effect on the human body if subjected to a current of 0 to 1 mA, 60 Hz, AC or 0 to 4 mA DC?Ans: Perception
What probable effect on the human body if subjected to a current of 1 to 4mA, 60 Hz, AC or 4 to 15 mA DC?Ans: Surprise
What probable effect on the human body if subjected to a current of 4 to 21 mA, 60 Hz, AC or 15 to 80 mA DC?Ans: Reflex action
What probable effect on the human body if subjected to a current of 21 to 40 mA, 60 Hz, AC or 80 to 160 mA DC?Ans: Muscular Inhibition
What probable effect on the human body if subjected to a current of 40 to 100 mA, 60 Hz, AC or 160 to 300 mA DC?Ans: Respiratory failure
What probable effect on the human body if subjected to a current of over 100 mA, 60 Hz, AC or 300 mA DC?Ans: Fatal
What is the effect of hydrogen surrounding the anode of a cell which increases the internal resistance of the cell?Ans: Polarization
What is the anode of a lead –acid cell?Ans: Lead peroxide
What is the cathode of a lead acid cell?Ans: Sponge lead
What is the anode of a NiCad Cell ?Ans: Hydroxide
What is the anode of a silver zinc cell?Ans: Silver oxide
What is the cathode of a silver zinc cell ?Ans: Zinc
What is the production of the hydrogen gas caused by a portion of the charge current breaking down the water in the electrolyte?Ans: Gassing
What is the shelf life of lithium organic cell and lithium inorganic cell?Ans: 20 years
In what charge is the charging rate determined by the battery voltage rather than a definite current value?Ans: Floating charge
What charge is used to keep a battery at full charge while the battery is idle or light duty?Ans: Floating charge
Floating charge is sometimes referred to as ___ and is accomplished with low current.Ans: Trickle charge
What is used when a battery must be recharged in the shortest possible time?Ans: Fast charge
Electrical safety precatutions must be observed. A fatal shock can occur from ___ ampere of current.Ans: 0.1
Voltages as low as ___ volts have been recorded as causing sufficient current to be fatal.Ans: 30
What type of extinguishers are used to extinguish electrical fires?Ans: CO2
Under favorable conditions, the body resistance may be as low as ___ ohmsAns: 300
The body resistance is possibly as low as ___ from temple to temple if the skin is broken.Ans: 100
In a voltage divider, bleeder current is usually determined by the ___ percent rule of thumb.Ans: 10
A theory of magnetism based upon the electron-spin principle.Ans: Domain Theory.
What action results in the increase in current that generates more heat and the cycle repeats itself until the diode draws excessive current?Ans: Thermal runaway
What is the faithful reproduction of a signal in an amplifier?Ans: Fidelity
What dc generators are designed to act as high gain amplifier?Ans: Amplidynes
What is the range of the dc resistance of most motor armatures?Ans: 0.05 to 0.5 ohms
What is usually the lamination thickness of the armature core of a small generator?Ans: 1/64 inches
Mechanical rotation of frequency is measured using a device called___.Ans: Tachometer
The rotation of frequency of recording devices and teletypewriter motors can be measured by the use of _____.Ans: Stroboscope.
What is an instrument that allows you to view rotating or reciprocating objects intermittently and produces the optical effect of a slowing down or stopping motion?Ans: Stroboscope
What is an electronic flash device in which the flash duration is very short, a few millionths of a second and can measure very rapid motion?Ans: Strobotac
What is a combination of watch and revolution counter?Ans: Chronometric tachometer
What type of bolometer is characterized as an increase in resistance as the dissipated power rises?Ans: Barreter
What type of bolometer is characterized by decrease in resistance as the power increases?Ans: Thermistor
What instrument is used for measuring radio frequency (rf) power?Ans: Thermocouple ammeter
Which of the following robots is used for machining processes?Ans: Cincinatti T3
Kuka spot welding has ___ degrees of freedom.Ans: 6
Exx1x
Ans: All positions
Exx2xAns: horizontal positions
Magnetic audio tapeAns: Parallel
Magnetic video tapeAns: Diagonal
Thickness of magnetic audio tape Ans: 1 mil
A sawtooth wave has a ____ added to become trapezoidal wave.Ans: resistor
Absent of current weldingAns: cool sub-interval
1.5 HAns: Air pot core
Who coined the term robotics?Ans: Isaac Asimov
Oldest weldingAns: Forge welding
KlystronAns: High achievable power output
Inert gasAns: MIG
Active gasAns: MAG
Antrophomorphic robot isAns: more maneuverable
It is also known as metal inert gas.Ans: Gas Metal Arc Welding (GMAW)
Robot with facial expressionAns: Kismet
Toy dinosaur robotAns: Pleo
Snap acting switchAns: Microswitch
Approach in which introduce factory automation technologyAns: Islands of automation
Degree of automatic.Ans: Level of automation
Orange, blue and gray diodeAns: IN368
It is the welding electrode comes forward and engage the metal pressing against the surface.Ans: squeeze interval
It is the welding in which the welding transformer energized and the current flows and create a weld.Ans: weld interval
It is the weld interval that is finishedAns: hold interval
Welding electrode is retractedAns: release interval
A time after release interval to the next start sequence.Ans: Standby interval.
It is a closed loop feedback control system in which one or more of the system signals represent mechanical motion.Ans: Servomechanism.
Exx3xAns: Flat
E60xx has a tensile strength of ___Ans: 60,000 psi
With AC or DC similar to E6010Ans: E6011
Major power supply of MIGAns: DCRP
Medium penetration Ans: E6013
Can be prevented by arc weldingAns: Arc flow
Faying surfaces in one spotAns: Resistance spot welding
Faying surfacesAns: Resistance seam welding
Resistance of the workAns: Resistance welding
Mass of 60-lb IR robotAns: 60 kg
Deep penetrationAns: Submerged arc
Deep penetrationAns: DC reverse
Medium penetration Ans: DC straight
Fast weldingAns: Flash welding
10,000 to 50,000 Hz weldingAns: High frequency welding
Image resolution Ans: Dot pitch
Voltage of dry electrolytic capacitorAns: 500 V
Apply electrostatic voltage in plastic Ans: Electroactive polymer
In electrolytic positive, ___ of the total heat.Ans: 2/3
Prevents coronaAns: Braid
450°F below…Ans: Soldering
above 450°F joining of two metalsAns: Brazing
Metal active gasAns: CO2
Multimeter on the lower center switchAns: Range switch
Multimeter on the lower left switchAns: Function switch
Aluminum D-ARsonval movementAns: Bobbin
Positive leadAns: Red
Negative leadAns: Black
Angular momentum of robotAns: Yaw
GaAs disadvantage Ans: more expensive
Disadvantage of Transformer to capacitive coupling
Ans: more expensive
A motor or transducer that converts energy (electrical, hydraulic, or pneumatic) into power used to produce motion or power. Ans: actuator
The ability of a robot to position its end effector at a programmed location in space.Ans: accuracy
Control signals that are processed by directly measuring quantities (voltages, resistances or rotation). This can be hydraulic, electronic or pneumatic. Ans: analog control
A robot or machine that resembles a human. Ans: android
A robot with rotary joints that can move much like a person’s arm. Ans: anthrophomorphic robot
An interconnected set of links and powered joints comprising a manipulator that supports or moves a wrist, hand or end effector. Ans: arm
The ability of a machine system to perceived anticipated or unanticipated new conditions, decide what actions must be performed under the conditions and plan the actions accordingly. The main areas of applications are expert systems and computer vision.Ans: artificial intelligence
Also known as assembly cell or assembly station. A concentrated group of equipment such as manipulators, vision modules, parts presenters, and support tables that are dedicated to compute assembly operations at one physical location.Ans: assembly
The use of any one several techniques to determine the presence or absence of features. This technique include simple mechanical probes and vision systems. Ans: automated inspection
Automatically controlled operation of an apparatus, process or system by mechanical or electronic devices that replace human observation, effort and decision. Ans: automation
A traveled path in space, usually referred to as a linear direction of travel in any of three dimensions. Ans: axis
A robot in which motions are controlled by driving each axis or degree of freedom against a mechanical limit stop. Ans: bang-bang robot
A platform or structure to which a robot arm is attached; the end of a kinematic chain of arm links and joints opposite to which grasps or processes external objects. Ans: base
A manufacturing unit consisting of two or more workstations or machines and the material transport mechanisms and storage buffers that interconnect them. Ans: cell
A manufacturing unit consisting of two or more cells, and the material transport mechanisms and storage buffers that interconnect them. Ans: center
An assembly between two closely related rigid members enabling on member to rotate in relation to the other around a mobile axis.
Ans: complex joint
The use of an interactive terminal workstation usually with graphics capability to automate the design of products. It includes functions such as drafting and fit-up parts.Ans: computer aided design (CAD)
Working from a product design likely to exist in a CAD data base, it encompases the computer based technologies that physically produce the product, including parts program preparation, process planning, tool design, process analysis and parts processing by numerically controlled machines. Ans: computer-aided manufacturing (CAM)
A numerical control system with a dictated mini or micro computer that performs the functions of data processing and control. Ans: computerized numerical control (CNC)
The unit of automatic work for a robot. Within a cycle, subelements called trajectories define lesser but integral elements. Each trajectory is made up of points where the robot performs an operation or passes through depending upon the programming.Ans: cycle (program)
The number of independent ways the end effector can move. It is defined by the number of rotational or translational axes through which motion can be obtained.Ans: degrees of freedom
The joint that connects the upper arm and forearm on a robot. Ans: elbow
Also known as end of arm tooling or simply a hand. The subsystem that links the mechanical portion of the robot (manipulator) to the part being handled or work on, and gives the robot the ability to pick yp and transfer parts and/or handle a multitude of different tools to perform work on parts. Ans: end effector
Robots with little if any computer power. Their only intelligent functions consist of learning a sequence of manipulative actions, choreographed by a human operator using a teach box. Ans: first generation robot system
Also known as nonservo robot or open robot. A robot with stoppoint control but no trajectory control.Ans: fixed stop robot
Multipurpose robots that are adaptable and capable of being redirected trained or used for new purposes.Ans: flexibility operational
An arrangement of machine tools that is capable of standing alone, interconnected by a workpiece transport system and controlled by a central computer.Ans: flexible manufacturing system (FMS)
Also known as pedestal robot. A robot with its base permanently or semi-permanently attached to the floor or bench. Such a robot is working at one location with a maximum limited work area and in many cases servicing only one machine.Ans: floor mounted robot
That portion of a jointed arm which is connected to the wrist and elbow Ans: forearm.
An overhead mounted, rectilinear robot with a minimum of three degrees of freedom and normally not exceeding six. Ans: gantry robot.
The grasping hand of a robot, which manipulates objects and tools to fulfill a given task. Ans: gripper
An approach used to introduce factory automation technology into manufacturing by selective application of automation.Ans: islands of automation.
The degree to which a process has been made automatic. Relevant to the level of automation are questions of automatic failure recovery, the variety of situations that will be automatically handled, and the conditions under which manual intervention or action by human beings is required.Ans: level of automation
An electrical switched positioned to be switched where a motion limit occurs, thereby deactivating the actuator that causes the motion. Ans: limit switch
A mechanism usually consisting of a series of segments or links, jointed or sliding to one another, for grasping or moving objects, usually in several degrees of freedom. Ans: manipulator
A method for the control of machine tool systems. A program containing all the information, in symbolic numerical form, needed for processing a workpiece is stored on a medium such as paper or magnetic tape. Ans: numerical control
Developing robot programs partially or completely without requiring the use of the robot itself. The program is loaded into the robot’s controller for subsequent automatic action of the manipulator. Ans: off-line programming
Software that controls the execution of computer programs, may provide scheduling, allocation, debugging data management, and other functions. Ans: operating systems
Also known as positioning. The consistent movement or manipulation of an object into controlled position and altitude in space. Ans: orientation
The equipment used in conjunction with the robot for a complete robotic system. This includes grippers, conveyors, parts positioners and parts or materials feeders that are needed with the robot. Ans: peripheral equipment
Also known as bend. The angular rotation of a moving body about an axis that is perpendicular to its direction of motion and in the same plane as its top side. Ans: pitch
Also known as photoelement or photosite. A digital picture or sensor element, picture is short for picture cell. Ans: pixel
The act of providing the control instructions required for a robot to perform its intended task.Ans: programming
The envelope of variance of the robot tool print position for repeated cycles under the same conditions. It is obtained from the deviation between the positions and orientations reached at the end of several similar cycles. Contrast with accuracy. Ans: repeatability
A reprogrammable, multifunctional manipulator designed to move a material, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks. Ans: robot
The science of designing, building and applying robots. Ans: robotics
Also known as twist. The rotational displacement of a joint around the principal axis of its motionj, particularly at the wrist.Ans: roll
A robot with a computer processes added to the robotic controller. This addition makes it possible to perform, in real time, the calculations required to control the motions of each degree of freedom in a cooperative manner to effect smooth motions of the end effector along predetermined paths. It also become possible to integrate simple sensors, such as force torque, and proximity into the robot system ,providing some degree of adaptability to the robot’s environment. Ans: second generation robot system
A controller that operates an application though a fixed sequence of events. Ans: sequencer
A robot driven by servomechanisms, that is, motors or actuators whose driving signal is a function of the difference between a commanded position and/or rate is measured actual position and/or rate.Ans: servocontrolled robot
An automatic control mechanism consisting of a motor or actuator driven by a signal that is a function of the difference between a commanded position and/or rate and measured actual position and/or rate.Ans: servomechanism
The manipulator arm linkage joint that is attached to the base. Ans: shoulder
The maximum velocity at which a manipulator joint can move; a rate imposed by saturation in the servoloop controlling the joint. Ans: slew rate
The use of two or more cameras to pinpoint the location of an object in a three dimensional space. Ans: stereo imaging
The detection by a robot though contact of touch, force, pattern slip and movement. It allows for the determination of local shape, orientation and feedback forces of a grasped workspace.Ans: tactile sensing
A robot system characterized by the incorporation of multiple computer processors, each operating asynchronously to perform specific functions. It includes a separate low level processor for each degree of freedom and a master computer supervising and coordinating these processors, as well as providing higher-level functions. Ans: third generation robot system
The orientation of a view with a video camera, in elevation. Ans: tilt
A continuous position control response to continuously changing input requirements. Ans: tracking
A movement such that all axes remain parallel to what they were. Ans: translation
The acquisition, movement thorugh space, and release of an object by a robot.Ans: transport
The portion of a jointed arm that is connected to the shoulder. Ans: upper arm
Also known as the robot operating envelope. The set of points representing the maximum extent or reach of the robot tool in a directions. Ans: work envelope
The envelope reached by the center of the interface between the wrist and the tool, using all available axis motions. Ans: workspace
A set of joints, usually rotational, between the arm and the hand or end effector, which allow the hand or end effector to be oriented relative to the workpiece. Ans: wrist
The angular displacement of a moving joint about an axis which is perpendicular to the line of motion and the top side of the body. Ans: yaw
What magnet is used in computer memory circuits? Ans: Ring magnet
What magnet is used in some meter circuits? Ans: Horseshoe magnet
“If the electrons of the atom in a material spin more in one direction than in the other, the material will become magnetized”. This refers to what theorem?Ans: The Domain theory of Magnetism
What theorem assumes that all magnetic materials are made up of magnetic molecules which, if lined up in north to south pole order, will be a magnet. If not lined up, the magnetic fields about the molecules will neutralize each other and no magnetic effect will be noted? Ans: Weber’s theory of magnetism
What do you call a short circuit having minimum resistance? Ans: Dead short
What refers to a continuation of current flow within an electrical cell when there is no external load? Ans: Local action
The amount of increase in the resistance of 1 ohm sample of the conductor per degree of temperature rise above 0°C is called what? Ans: Temperature coefficient of resistance
What do you call the resistance to current leakage through the insulation? Ans: Insulation resistance
What is the common name for enamel insulated wire? Ans: Magnet wire
What term is general one and usually applies only to the larger sizes of conductors? Ans: Cables
The process of applying thin coat of solder to materials prior to their being soldered. Ans: Tinning
The addition of atmospheric oxygen to metal to form rust, or to cause a breakdown in the internal construction of the metal. Ans: Oxidation
What refers to a continuation of current flow within an electrical cell when there is not external load? Ans: Local action
A continuous jacket of lead molded around a single conductor or multiple conductor cable.Ans: Lead sheath
What do you call the force exerted on an insulator by the voltage in a conductor?Ans: Electrostatic stress
The discharge of electricity from a conductor with a high potential.Ans: Corona
A material that removes oxides from surfaces to be joined by soldering or welding.Ans: Flux
A synthetic mixture of rosins that is flexible and used as an insulating material. Generally used as an insulator for low and medium range voltages. Ans: Thermoplastic
The capacity of a soldering iron to generate and maintain a satisfactory soldering temperature while giving up heat to the material being soldered. Ans: Thermal inertia
What is the working voltage of a dry electrolytic capacitor? Ans: 500 V
If arcing should occur between the plates of an oil filled capacitor, the oil will tend to reseal the hole caused by the arcing. Such a capacitor is referred to as ____ capacitor. Ans: self-healing
The maximum voltage that can be steadily applied to the capacitor without the capacitor breaking down (shorting) is called ____ of the capacitor. Ans: working voltage
What is meant by “local action”? Ans: Current flow in cell with no external load.
The left side of the pulse Ans: Leading edge
The right side of the pulse Ans: Trailing edge
What is the process by which an atoms gain or losses electrons?Ans: Ionization
Any group of energy levels that results from the close proximity of atoms in a solid. Ans: Energy bands
How many pulsations per revolution have the output voltage of an elementary single coil dc generator? Ans: Two
How many commutator segments are required in a two-coil generator? Ans: Four
What is the distortion of the main field due to the effects of armature current? Ans: Armature reaction
What type of prime mover requires a specially designed high speed alternator? Ans: Steam turbine
What type of rotor is used in slower speed alternators?Ans: Salient pole rotor
What type of rotor is wound in a manner to allow high-speed use without flying apart? Ans: Turbine driven type rotor
What term is used to denote the difference in speed between the rotor which is always somewhat less than the speed of the rotating field?
Ans: Slip
What mechanical device reverses armature connections in motors and generators at the proper instant so that current continues to flow only in one direction? Ans: Commutator
What motor characteristic is affected by counter emf? Ans: Speed
How is EPROM erased? Ans: with a burst of ultraviolet light
Whenever data is transferred between devices, it involves the exchange of prearranged signals. What is this process called? Ans: Handshaking
What test is used to check for opens (or to see if the circuit is complete or continuous) and is accomplished with an ohmmeter? Ans: Continuity test
What type of circuits are caused by some conducting part of the circuit making contact either directly or indirectly with the metallic structure of the ship or chassis? Ans: Ground circuits
Shunts are usually made from what alloy? Ans: Manganin
What property of shunt is desired because of the heavy currents that often flow through shunts producing heat?Ans: Zero-temperature coefficient
In D’Arsonval meter, many turns of fine wire would be used, each turn adding more effective length to the coil. The coil is wound on an aluminum frame called ___. Ans: bobbin
What is an important point to remember when you are making an accurate resistance measurement? Ans: “Zero” the meter each time you select a new range.
BJT better than FET Ans: radio receiver
Wineglass Ans: Plasma arc welding
… plasma Ans: Plasma arc welding
Slow speed Ans: Salient pole
High speed Ans: Turbine driven type rotor
Differentiation Ans: Submerged
Comparison solenoid Ans: Relay fixed core
Human arm Ans: Serial robot
Input display signal voltage Ans: Vertical deflection coil
Replacing DC motor/recently used Ans: Piezo motor
Rapid discharge of electrical energy Ans: Percussion welding
Hydrogen Electrode Ans: E7018
False Ans: Air has the concentrated magnetic field
Electron gun tube Ans: CRT
Electron field tube Ans: Electron beam
Multicavity Klystron Ans: Variable electron speed
Fuse Ans: Quick break type
Magnetic frequency increases Ans: Power output decreases
Cause of electrons due to the longitudinalAns: Magnetic field
Along a jointAns: Upset welding
Fastest memoryAns: Flash memory
Tungsten electrodeAns: TIG
Use of non-interlaced monitorAns: Fast graph
CMOS disadvantageAns: cannot handle high power
TTLAns: least susceptible to noise
E stands forAns: American Wire Electrode
Exceeding 450°F
Ans: Brazing
Not exceeding 450°FAns: Soldering
Generators usedAns: Magnetic
Battery used as Ans: chemical
Responsible of pulsating DCAns: Commutator
Low voltage high powerAns: Center tapped Full Wave
Oldest 1940 general magnetic phenomenonAns: Colding or cold contact
JointsAns: Direct Kinematics
End effector Ans: Inverse Direct Kinematics
Nothing but to memory Ans: Flag field
Unwanted connection Ans: Fault connection
Frequency synthesizer used as Ans: Divider
Output amplitude Ans: Amplitude stability
DC motor is preferred as driver in robotics because Ans: it can withstand large overload
Welding is not used direct source because Ans: it is impracticable to draw heavy currents
Atomic hydrogen is long lived because Ans: ac is used
RF power amplifier Ans: Common base
Choke Ans: passes dc but not RF
Multivibrator Ans: Common emitter or common source
Algorithm better than ZMP Ans: Dynamic balancing
One feet with smallAns: Hopping
Automatic weldingAns: 5 intervals
Control grid of a tubeAns: gate of a FET
Impedance mismatch reactance outputAns: Transformer
Laminated coreAns: reduces eddy current loss
No load loss but not electrical lossAns: Windage
Manganese Dioxide Alkaline Acid Ans: Alkaline Cell
Draws large amount of current Ans: Rheostat
Increase RL Ans: Improved Efficiency
Single coil Ans: Elementary generator
3 classifications of robot Ans: Anthrophomorphic, SCARA, and articulated
Connects arm and end effectors Ans: Wrist
____ for bones, ____ for muscle and ____for degrees of freedom. Ans: links, actuator, and joints
Early actuator Ans: Elastic nanotube
Changing of electric energy Ans: Electroactive polymer
Variable speed Ans: DC generator
Constant speed Ans: AC generator
More robot than worker Ans: Japan
Transient suppression prevents
Ans: diode failure
Tunnel diode Ans: Dr. Leo Esaki
Zener Diode Ans: Dr. Carl Zener
Varactor diode uses Ans: Frequency stability
2 terminal communicate Ans: Handshaking
Highest fidelity Ans: Class A
Portion Ans: Class AB
FET amplifier Ans: Class AB2
Medium penetration Ans: E6013
Oxy fuel arc Ans: Oxy fuel gas welding
Electrical requirement of arc welding Ans: high open circuit voltage
Horizontal oscilloscope Ans: Time/division
Joining of metals Ans: Welding
Radio using tubes Ans: Bulk and heavy
The purpose of I in PIN diode Ans: minimizes junction capacitance
1/16 to 5/16 in in diameter Ans: American Welding Society
Degrees of freedom for General purpose effectors Ans: 20
Deep penetration welding Ans: Submerge arc welding
JFET except Ans: transconductance
Pinch off voltage Ans: Transconductance is zero
Formula for IC with leakage current Ans: IC = βIB + (β+1)ICBO
IE Ans: IE = IC - ICBO
α ICQ
Ans: ICQ = βIBQ + ICEO
IEQ
Ans: IEQ = ICQ + IBQ
Increase temperature leakage current Ans: ICBO = ICBO
(T2-T1)/10
Charge of a capacitor Ans: Q = CV
Charge Ans: Q = Qo (1-e(-t/RC))
Dependent on gap Ans: Charge efficiency
NRZI means Ans: Non-return to zero invert
Pilot cell Ans: identifies the condition of the battery
More likely to occur than zener breakdown because lightl doped Ans: Avalanche breakdown
How wire Ans: measure dc and ac
Dielectric constant of mica Ans: 6
Buck boost lossless Ans: D = (V2)/(V1+V2)
Buck Ans: D = V2/V1
Op-amp filter Ans: Polysterene
TTL Ans: open circuit high level
I2L Ans: bipolar saturated logic
EAROM Ans: Degrade data if used
6 rectifying elements Ans: Gratz rectifier
Superconductivity thin film memory consisting of a superconducting inductor Ans: Permistor
Register and counters are the same because Ans: they have the same array of flip flop and gates
High Q Ans: High selectivity
2 principles of detector Ans: Rectifier and filter
Microprocessor Ans: ALU and control unit
CPUAns: ALU and control unit
Simulate Ans: Simulator
Servocontrolled robot Ans: Soft stop
Nonservo robot Ans: Hard stop
Lowest resistivity at 293 K Ans: Copper
BIG elements Ans: Trivalent
PAA elements Ans: Pentavalent
Analog preferred than digital because Ans: of measuring signal strength
Opposing torques Ans: Deflecting and restoring torques
Code that… Ans: Absolute code
Equal ripple Ans: Eliptic filter
IlluminanceAns: Lux
Ripple sharp cutoff Ans: Chebyshev filter
Adds all harmonics
Ans: Sawtooth
Odd harmonicsAns: Square
All even harmonics Ans: Push pull
The single grid of vacuum Ans: Control grid
In low frequency cutoff, amplitude decreases by ___ from midrange value Ans: 3 dB
Change in audio rangeAns: 1 dB
EXCEL…
Fiber Optics (Chapter 11: Past Board Excel)
ECE Board Exam April 2001Which of the following refers to the relative refractive index difference of single mode fibers?0.1 - 0.3 %
ECE Board Exam November 2000A parameter of light beam that do not change the quality when it enters one medium from another.Frequency
ECE Board Exam April 2000Which of the following limits the top speed of transmitting information in fiber optic communication?Detector speed
ECE Board Exam November 1999Type of multi-channel signal transmission in the optic fiber communication that uses twisted pair coupler to transmit two signals of different wavelengths.Frequency-division multiplexing
ECE Board Exam April 1999Best applies to an optical fiber core.A higher refractive index than the cladding
ECE Board Exam November 1998How many times bigger does the bandwidth of a fiber optic multimode have over cable?100 times bigger
ECE Board Exam April 1998What law does a light travelling in an optical fiber follow?Snell's
ECE Board Exam November 1997Band of light waves, that are too short to be seen by human eye.Ultraviolet
ECE Board Exam April 1997Insertion loss of connector-type splices for a single-mode fiber cable.0.38dB
ECE Board Exam November 1996An object father from a converging lens than its focal point always has an ________ image.inverted
ECE Board Exam March 1996The dielectric material of an optical fiber surrounding the core.Cladding
ECE Board Exam April 2001An optical time domain reflectometer used in fiber optic communication is not intended to determine one of the following:Kind of multiplexing
--------------------- An optical time domain reflectometer used in fiber optic communication-------Refractive indexLoss per kilometerLength of fiber
ECE Board Exam November 2000In wire communications system using fiber optic, the packing fraction is related to one of the following statements when referred to fiber optic bundle.Ratio of the total cross-sectional area to the total cross-sectional area of the fiber bundle
ECE Board Exam April 2000Why are fiber optic cables considered less expensive compared to coaxial cables in communication system?Use of less repeaters
ECE Board Exam November 1999An optic fiber regenerator which is used in communication is consisting of a ________ to clean up and amplify digital data moving in one direction and a similar system for the opposite direction.transmitter and receiver
ECE Board Exam April 1999How do you account the effect of light intensity on the refractive index of a fiber optic?Increases
ECE Board Exam November 1998One of the following referred to as a major component of an optical time domain reflectometer.Pulse generator laser
ECE Board Exam April 1998__________ generates light beam at a specific visible frequency.Laser
ECE Board Exam November 1997The most common device used as a light detector in fiber optic communication system.APDs
ECE Board Exam April 1997A non-coherent light source for optical communications system.LED
ECE Board Exam November 1996The loss in signal power as light travels down a fiber isattenuation
ECE Board Exam March 1996It is made from semiconductor material such as aluminum-gallium-arsenide or gallium-arsenide-phosphide.Light emitting diode
ECE Board Exam April 2001How much bigger does the bandwidth of a single mode fiber optic have over the multimode fiber?20 times bigger
ECE Board Exam November 2000Which of the following refers to the bandwidth of optical fiber?1 MHz - 500 MHz
ECE Board Exam April 2000Refers to a characteristic of a multimode fiber optic.Cladding thickness is greater than the radius of the core and the diameter of the core must be much greater than the wavelength of the light to be carried.
ECE Board Exam November 1999What do you call the loss in signal power as the light travels the fiber optic?Attenuation
ECE Board Exam April 1999 One of the characteristics of a fiber optic used in order to carry light in several modes of propagation or to become a multimode fiber.Diameter of the core must be very muuch greater than the wavelength of the light to be carried.
ECE Board Exam November 1998What kind of effect is referred to a varying light producing a varying voltage output of a detector? Photovoltaic effect
ECE Board Exam April 1998Quantity that do not change when a beam of lifgt enters one medium to anotherFrequency
ECE Board Exam April 1997Type of fiber that has the highest modal dispersion.Step-index multimode
ECE Board Exam November 1997Calculate the energy of the photon of infrared light intensity at 1.55 um.
ECE Board Exam November 1996The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted is known as __________.mode
ECE Board Exam March 1996An absorption loss caused by valence electrons in the siica material from which fibers are manufactured.Ultraviolet absorption
ECE Board Exam April 2001Which of the following is not a major component of an optical time domain reflectometer used in fiber optic communication?vertical and horizontal plates
-------------------- major component of an optical time domain reflectometer used in fiber optic communication---------------------LaserBeam splitterPulse generator
ECE Board Exam November 2000Which of the following is a part of an optical time domain reflectometer?Beam splitter
ECE Board Exam April 2000This refers to a certain material which is most sensitive to light.Photoresist
ECE Board Exam November 1999Referred to as a light source of fiber optic which supplies level of 5to 7 milliwats and having a narrow spectrum of emission.Injection laser diode
ECE Board Exam April 1999Most likely, how many times would a fiber optic break in a span of thirty years?2 - 3 times
ECE Board Exam November 1998An advantage of optic fiber rejecting an induced noise signal from magnetic field or solar storm fluxImmunity to noise
ECE Board Exam April 1998Which of the following colors of light rays has the shortest wavelength?Violet
ECE Board Exam April 1997Fiber optic cable operates near ________ frequencies.800 THz
ECE Board Exam November 1997If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time?
ECE. Board Exam November 1996Proposed the used of a clad glass fiber as a dielectric waveguideBockham and Kao
ECE Board Exam November 2000ln electronic communications where fiber optic material is used, a reflectedwave is a possibility. what happen to the polarization of this reflected wavewhen compared to its original form?Shifts to 180 degrees
ECE Board Exam April 2000The effect of multimode propagation caused the rays leaving the fiber tointerfere constructively and destructively as they leave the end of the fiberthis effect is called _________.modal delay spreading
ECE Board Exam November 1999 What is the wavelength for deep violet light?500 nmeter
ECE Board Exam April 1999A device in the fiber optic that is used to attenuate the reflected signal from the polished end of the fiber which has a possibility of developing into a noise.Isolator
ECE Board Exam November 1998One of the advantages of the fiber optic which is referred to the volume of capacity of signals it can carryBandwidth
ECE Board Exam April 1998Circuit used to amplify the optical signal in fiber optics communications links.Optical repeater
ECE Board Exam November 1997A device that reduces the intensity of light in fiber optics communication systemsOptical attenuator
ECE Board Exam April 1997Lifetime of ILDs50.000 h
ECE Board Exam November 1996What is the stage of the sand becoming a silicon?Molten
ECE Board Exam November 2000One of the major limitations of a plastic fiberoptic used in communicationDue to its high losses
ECE Board Exam April 2000One of following is considered the largest source of signal power loss in theuse of fiber optic as communications medium such as due to misalignment.ConnectionECE Board Exam NOvember 1999One of the following is related to the application of solid material as a medium where light travels.medium where Ilght travels. apphcatlon of 5DHd mater-ja}; as 3Fiber optics
ECE Board Exam April 1999Which of the following is not considered as one of the causes for the loss of signal power as light travels through a fiber optic?Inter-modulation----------------causes for the loss of signal power as light travels through a fiber optic-----------------ScatteringFiber bendingAbsorption
ECE Board Exam November 1997The core of the optical fiber has _______a higher index of refraction than the cladding
ECE Board Exam November 1997Loss due to the diffraction of light when it strikes on the irregularities formedduring the manufacturing process of the fiber optics.Rayleigh scattering loss
ECE Board Exam November 1996If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time?
ECE Board Exam November 2000A phenomenon which causes the speed of light rays propagation in the fibermaterial changes, as it passes through different medium in the fiberRefraction
ECE Board Exam April 2000At what intenial does a fiber optic needs a repeater in communicationssystem?30 to 300 miles
ECE Board Eanm November 1999Referfeq to as a limit in reducing further the loss of signal passing through afiber optic caused by scattering.Rayleigh effect
ECE Board Exam April 1999These are band of light wavelengths, that are too short to be seen by the human eye.Ultraviolet
ECE Board Exam November 1998A quarter wavelength device made of crystalline calcite that changes polarization in the optic fiber communicationRetarder
ECE Board Exam April 1999At what power levels does fiber optic have when used in electronic communications?Range of micro to milliwatts
ECE Board Exam November 1998One of the following is among the types of fiber optics used in electronics communication.Semi-graded multimode
ECE Board Exam November 1998How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic?By application of antireflection coating ECE Board Exam November 1998What is the device use in used in fiber optic communication which consist of a receiver transmitter use tc clean up and amplify digital data moving in one direction and another in opposite direction? Optic regenerator
ECE Board Exam November 2000An advantage of fiber optic over co-axial cable as a result of coupling signalsfrom one to the other due to changing magnetic field in one or both.Crosstalk
ECE Board Exam April 2001What is the index of refraction of a certain substance if light travels throughthe substance at 100 meters at a time is to 140 meters to air'?
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Saturday, June 16, 2012
Satellite Communications (Chapter 10: Past Board Exce)
ECE Board Exam April 2001What balance the gravitational pull of the earth to allow the satellite to stay on its orbit?Centripetal force
ECE Board Exam November 2000Satellite that rotates around the earth in a low-altitude elliptical or circular pattern.Nonsynchronous satellite
ECE Board Exam April 1999In a transoceanic satellite conversation, how much is the typical delay before a reply is heard?600 ms
ECE Board Exam November 1999What are the repeaters inside communications satellite known for?Transponders
ECE Board Exam April 2000Under a circular satellite orbiy, how high is a certain satellite located above the surface of the earth if the total satellite height is 9869 miles?
ECE Board Exam November 1998 Is a kind of satellite which has a period of revolution equivalent to the period if rotation of the
earth about its axis. Geosynchronous satellite
ECE Board Exam April 1998A radio land station in the land mobile service.Base station
ECE Board Exam November 1997The use of telecommunication for automatic indicating or recording measurement at the distance from the measuring instrument.Telemetry
ECE Board Exam April 1997_______________ is the horizontal pointing angle of an antenna.Azimuth
ECE Board Exam November 1996How many satellite orbital slots are requested by the Philippine government from ITU?6
ECE Board Exam MArch 1996The point on satellite orbit, closest to the earth isperigee
ECE Board Exam April 2001A mobile service between base stations and land mobile stations or between land mobile stations.Mobile service
ECE Board Exam November 2000Which of the following refers to the basic component of a communication satellite receiver?Transponder
ECE Board Exam April 2000Determine from the following the basic technique used to stabilize a satellite.Spin
ECE Board Exam November 1999A space distance iin satellite communication from the earth, to or greater than 2,000,000 kilometers is referred to as ___________.deep space
ECE Board Exam April 1999How many satellites does the GPS system consist?24 satellites
ECE Board Exam November 1999Which point on the satellite orbit is closest to the earth?perigee
ECE Board Exam November 1998Which of the following is refers to the smallest beam of a satellite antenna's radiation pattern?spot beam
ECE Board Exam April 1998A major and basic advantage for the use of klystron.Hiigh power
ECE Board Exam November 1997Station in the mobile service not intended to be used while in motion.Land station
ECE Board Exam April 1997__________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency.LNB
ECE Board Exam November 1996Collects very weak signals from a broadcast satellite.Satellite dish
ECE Board Exam March 1996It is a spacecraft replaced in orbit around the earth carrying onboard microwave receiving and transmitting equipmentsCommunications satellite
ECE Board Exam April 2001A what apogee in an elliptical orbit must a geosynchronous satellite be initially stationed before it is finally fired into its final geostationary orbit?22,300 miles
ECE Board Exam November 2000Satellite orbit around the earth are either:they are either circular or elliptical
ECE Board Exam April 2000Satellite system or part of a satellite system, consisting of only one satellite and the cooperating stations.Satellite network
ECE Board Exam November 1999A resultant effect in launching a satellite from the earth caused by both forward motion away
from the earth that provides inertia tending the satellite to travel in straight line upwards and the gravitational pull towards the earth is referred to as ___________.centripetal acceleration
ECE Board Exam November 1998Which of the following refers to the first active satellite?Sputnik 1
ECE Board Exam April 1998A band where most military satellite often operate.X
ECE Board Exam November1997Known to be the first satellite capable to receive and transmit simultaneously.Telstar I
ECE Board Exam April 1997What kind of battery panels are used in some advanced satellites?Gallium arsenide solar panels
ECE Board Exam November 1996Satellite signal transmitted from a satellite transponder to earth's station.Downlink
ECE Board Exam November 1999In satellite communications where satellites revolve in an orbit that forms a plane passing through the center of gravity of the earth, this center is called ____________geocenter
ECE Board Exam April 1998The use of telecommunication for the transmission of signals to initiate, modify or terminate functions of equivalent at a distance.Telecommand
ECE Board Exam November 1997The use of telecommunication for the transmission of signals to initiate modify or terminate functions of equipment at a distance.Telecommand
ECE Board Exam April 1997Footprint refers to coverage area in the globe.Satellite coverage
ECE Board Exam November 1996The first commercial satelliteEarly bird
ECE Board Exam November 1996What band does VSAT first operate?C-band
ECE Board Exam April 2001Which part of transponder converts the received signal to another lower frequency?Mixer
ECE Board Exam April 1998In satellite communications, the geostationary satellites are conveniently located with respect to the equator at __________.0 degrees latitude
ECE Board Exam November 1997The Ku-band in the satellite service.14/11 GHz
ECE Board Exam April 1997Asia Sat I covers how many countries in Asia?38
ECE Board Exam November 1996Satellite engine usesion propulsion system
ECE Board Exam April 2001How do you increase or double the channel capacity of a satellite without increasing the frequency bandwidth?Re-use frequency
ECE Board Exam April 1998A satellite beam that covers almost 42.4% of earths surface.Global beam
ECE Board Exam November 1997Receives and collects satellite signals from a broadcast satellite.Satellite disk
ECE Board Exam April 1997Sound intensity level is __________10 log I/Iref
ECE Board Exam November 1996The first passive satellite transponder.Moon
ECE Board Exam April 1998The most common application of satelliteCommunications
ECE Board Exam November 1997Radio communication operation service between mobile and land stations or between mobile stations.Mobile service
ECE Board Exam April 2001Referred to as function and/or a designed of a double conversion satellite transponder.Equipped with two mixers
ECE Board Exam November 2000How does spatial isolation technique in satellite communications avoid interference?Employment of highly directional spot-beam antennas
ECE Board Exam April 1998One of the first satellite systems catering personal based communications services scheduled for operation.Iridium system
ECE Board Exam NOvember 1997A radio communications service used in radio regulation between specified fixed points provided primarily for the safety of air navigation and for the regular efficient and economical air transport.Aeronautical Fixed Service
ECE Board Exam November 1999When do you consider that there is a satellite pass, having reference from the ground?When satellite passes at its orbit at 90 degrees from its azimuth.
ECE Board Exam April 1998Station located on an object which is beyond and is intended to go beyond the major portion of the earths athmospehere.Space Station
ECE Board Exam November 1997An earth satellite whose period of revolution is equal the period of rotation of the earth about its axis.Geosynchronous
ECE Board Exam April 1998Known as the satellite transmitted signal from a satellite transponder to earths station.Down link
ECE Board Exam November 1997A satellite receives an uplink frequency of __________ MHz from a ground station of 3700 MHz.
ECE Board Exam April 1998What do you call the signal booster installed on the antenna dish of satellite receiver?Low noise amplifier
ECE Board Exam November 1997Which of the following refers to the smallest beam of satellite antennas radiation pattern?Spot Beam
ECE Board Exam April 1998Referred by a radio regulation as the station in the mobile service not intended to be used while in motionLand Station
ECE Board Exam November 1997Satellite system or part of a satellite system, consisting of only one satellite and the operating earth station.satellite network
ECE Board Exam April 2001Typical bandwidth of a communications satellite.500 MHz
ECE Board Exam November 2000An area on earth covered by a satellite radio beam.Footprint
ECE Board Exam April 1999A twenty four (24) satellite system used in modern telecommunications to determine a location(s) on the surface of the earth.GPS
ECE Board Exam April 2001Which type of satellite transponder improves the S/N ratio which demodulates the up-link signal to recover the baseband signals and use them to remodulate the downlink transmitter?Baseband
ECE Board Exam April 1998In shipboard satellite dish antenna system, azimuth is referred as the __________horizontal aiming of the antenna
ECE Board Exam November 1997Refers to a land station in a maritime mobile service.Coast station
ECE Board Exam November 1998__________ is known to be the first satellite capable of receiving and transmitting simultaneously.Telstar I
ECE Board Exam April 1998What is the frequency range of C-band?3.4 to 6.424 GHz
ECE Board Exam November 1997An area on the surface of the earth within the boresight of the steerable satellite beam intended to be pointed.Effective boresight area
ECE Board Exam April 1998What is the approximate percentage of earth's coverage of a geostationary satellite at zero degree elevation?42.5 %
ECE Board Exam April 2001One of the following devices in satellite transponder serves as output of the receive antenna.low noise amplifier
ECE Board Exam November 2000In a re-use frequency technique of increasing satellite channel capacity of corresponding transponders, how do you control the antenna used to prevent interference?High directional antenna
ECE Board Exam November 2000Refers to a mobile earth station in the mobile-satellite service located on board shipShip earth station
ECE Board Exam April 2001A technique in satellite communications which uses a highly directional spot-beam antenna to prevent interference from frequency sharing.Frequency re-use technique
ECE Board Exam November 2000How do you determine the satellite location in latitude and longitude measurement?Designate a point on earth directly below the satellite
ECE Board Exam November 2000A point in the satellite orbit known to be the closest location to the surface of the earth.Perigee
ECE Board Exam November 2000Which satellite transponder has the most number of mixers?Double-conversion 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Satellite
Monday, June 4, 2012
Microwave Communications (Chapter 9: Past Board Excel)
ECE Board Exam April 2001Which of the following will you avoid in the construction of a microwave station?Long horizontal runs
ECE Board Exam November 2000Radio frequency where waveguides are not used extensively.150 MHz
ECE Board Exam April 2000Term used to describe a process of approaching a desired point by directing the vehicle towards that pointHoming
ECE Board Exam November 1999A system which does not refer to a technique in reducing the propagation errors in navigational system such as multipath effectsPulse transmission
ECE Board Exam April 1999Which of the following is a navigational equipment which utilizes a ground radar system to determine the position of a plane during its approach?GCA
ECE Board Exam November 1998_____________ is referred as the difference between available power and power budget.Power margin
ECE Board Exam April 1998Space diversity transmission means transmitting and receiving on __________.two or more antennas operating on the same frequency
ECE Board Exam November 1996One of the reasons why FDM is being replaced by TDM isnoise is amplified with voice when an FDM system is used
ECE Board Exam November 1996What is the baseband frequency of standard FDM basic supergroup?312 to 552 kHz
ECE Board Exam March 1996The k-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to __________4/3
ECE Board Exam March 1996LORAN is navigational system used primarily for _________obtaining your fixed location over a large distances
ECE Board Exam April 2001What navigational system technique uses an antenna directivity to reduce an undesired multipath signals?LORAN-C
ECE Board Exam November 2000In microwave frequencies, the LOS distance is something extended through the occurrence of ____________ducting
ECE Board Exam April 2000Which of the following if not a part of the navigational radar?Duplexer------------- part of navigational radar-----------PulserDisplay unitSynchronizer
ECE Board Exam November 1999How do you account the effect of selective fading on the transmitted signal in terms of its bandwidth?more affirmative at wider bandwidth
ECE Board Exam April 1999Frequencies most affected by knife-edge refraction.
VHF and UHF
ECE Board Exam April 1998Refers to an effect of selective fading.A fading effect caused by phase difference between radio wave components of the same transmission, as experienced at the receiving station.
ECE Board Exam November 1996When the clearance above the obstruction is equal to the radii of even Fresnel zones at the point of reflection the RSLis decreased
ECE Board Exam March 1996LORAN is a navigation system used primary forobtaining fixes over large distances
ECE Board Exam November 1966When the value of k increases, the effective result is _______ of the equivalent curvatures.flattening
ECE Board Exam March 1996TACAN is a navigational aid providing _________bearing and distance indication
ECE Board Exam November 1996If Ns = 250 determine the earth radius k-factor.
ECE Board Exam March 1996A one-hop, full duplex, microwave system is in a space diversity arrangement. Determine how many receivers in all are used?2
ECE Board Exam November 1996A microwave communications system space loss calculation formula is92.4 + 20 log F + 20 log D
ECE Board Exam March 1996Radio fading resulting from obstruction losses.Log normal fading
ECE Board Exam April 1998Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna.Circulator
ECE Board Exam November 1996What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path?Frequency
ECE Board Exam November 1996What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz?
ECE Board Exam November 1996Low-power radar usesIMPATT
ECE Board Exam November 2000A component of a microwave station that samples signal traveling in one direction down to the transmission line.Directional coupler
ECE Board Exam April 2000A navigational error which is caused by reflection of obstruction close to the location of navigational aid having a normal concern on directional bearing.Site error
ECE Board Exam April 1999An aircraft deviation measured by an ILS localizer.Horizontal
ECE Board Exam April 1998Which of the following systems is not used in radio detection and ranging?Amplitude modulation
----------- systems used in radio detection and ranging----------Frequency shiftFrequency modulationPulse radar
ECE Board Exam April 1997A microwave system that requires the use of repeater.Intervening system that requires the use of repeater.Distances involved are greater
ECE Board Exam November 1996Space diversity transmission means transmitting and receiving ontwo or more antennas operating on the same frequencies
ECE Board Exam April 1997RADAR meansRadio Detection and Ranging
ECE Board Exam November 2000Which band in the radio spectrum does the radio navigational system Omega transmit?VLF
ECE Board Exam November 1998Which of the following is not a common microwave application?Mobile radio
------------- common microwave application --------------RadarData transmissionSpace communications
ECE Board Exam April 1998What do you call a circuit that controls the magnetron output?Modulator
ECE Board Exam April 1997A microwave link between the earth station and the down-town terminalTerrestrial link
ECE Board Exam November 1997Two or more antennas separated by 9 wavelengths are used.Space diversity
ECE Board Exam April 2000In radio navigation, one of the following deviations of an airplane is determined by an ILS localizer.Horizontal
ECE Board Exam April 1997The advantage of periscope antenna in microwave.Shorten waveguide link
ECE Board Exam April 2000In navigational system, one of the following indication is provided by the localizer unit of the ILS.A horizontal deviation of an airpalne from its optimum path of descent along the axis of the runway.
ECE Board Exam April 1999Referred to as the cycle time difference between the master and the slave signals to reach the
receiver in the operation of loran navigational equipment.Time delay
ECE Board Exam April 1999Which of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?Weak part
ECE Board Exam April 1999What is being measured in radar theory to complete the determination of a distance to a target or object, after a high radio frequency signal is transmitted to a target?Echo time off the object to the source
FIBER OPTICS…
Fiber Optics (Chapter 11: Past Board Excel)
ECE Board Exam April 2001Which of the following refers to the relative refractive index difference of single mode fibers?0.1 - 0.3 %
ECE Board Exam November 2000A parameter of light beam that do not change the quality when it enters one medium from another.Frequency
ECE Board Exam April 2000Which of the following limits the top speed of transmitting information in fiber optic communication?Detector speed
ECE Board Exam November 1999Type of multi-channel signal transmission in the optic fiber communication that uses twisted pair coupler to transmit two signals of different wavelengths.Frequency-division multiplexing
ECE Board Exam April 1999Best applies to an optical fiber core.A higher refractive index than the cladding
ECE Board Exam November 1998How many times bigger does the bandwidth of a fiber optic multimode have over cable?100 times bigger
ECE Board Exam April 1998
What law does a light travelling in an optical fiber follow?Snell's
ECE Board Exam November 1997Band of light waves, that are too short to be seen by human eye.Ultraviolet
ECE Board Exam April 1997Insertion loss of connector-type splices for a single-mode fiber cable.0.38dB
ECE Board Exam November 1996An object father from a converging lens than its focal point always has an ________ image.inverted
ECE Board Exam March 1996The dielectric material of an optical fiber surrounding the core.Cladding
ECE Board Exam April 2001An optical time domain reflectometer used in fiber optic communication is not intended to determine one of the following:Kind of multiplexing
--------------------- An optical time domain reflectometer used in fiber optic communication-------Refractive indexLoss per kilometerLength of fiber
ECE Board Exam November 2000In wire communications system using fiber optic, the packing fraction is related to one of the following statements when referred to fiber optic bundle.Ratio of the total cross-sectional area to the total cross-sectional area of the fiber bundle
ECE Board Exam April 2000Why are fiber optic cables considered less expensive compared to coaxial cables in communication system?Use of less repeaters
ECE Board Exam November 1999An optic fiber regenerator which is used in communication is consisting of a ________ to clean up and amplify digital data moving in one direction and a similar system for the opposite direction.transmitter and receiver
ECE Board Exam April 1999
How do you account the effect of light intensity on the refractive index of a fiber optic?Increases
ECE Board Exam November 1998One of the following referred to as a major component of an optical time domain reflectometer.Pulse generator laser
ECE Board Exam April 1998__________ generates light beam at a specific visible frequency.Laser
ECE Board Exam November 1997The most common device used as a light detector in fiber optic communication system.APDs
ECE Board Exam April 1997A non-coherent light source for optical communications system.LED
ECE Board Exam November 1996The loss in signal power as light travels down a fiber isattenuation
ECE Board Exam March 1996It is made from semiconductor material such as aluminum-gallium-arsenide or gallium-arsenide-phosphide.Light emitting diode
ECE Board Exam April 2001How much bigger does the bandwidth of a single mode fiber optic have over the multimode fiber?20 times bigger
ECE Board Exam November 2000Which of the following refers to the bandwidth of optical fiber?1 MHz - 500 MHz
ECE Board Exam April 2000Refers to a characteristic of a multimode fiber optic.Cladding thickness is greater than the radius of the core and the diameter of the core must be much greater than the wavelength of the light to be carried.
ECE Board Exam November 1999What do you call the loss in signal power as the light travels the fiber optic?Attenuation
ECE Board Exam April 1999 One of the characteristics of a fiber optic used in order to carry light in several modes of propagation or to become a multimode fiber.Diameter of the core must be very muuch greater than the wavelength of the light to be carried.
ECE Board Exam November 1998What kind of effect is referred to a varying light producing a varying voltage output of a detector? Photovoltaic effect
ECE Board Exam April 1998Quantity that do not change when a beam of lifgt enters one medium to anotherFrequency
ECE Board Exam April 1997Type of fiber that has the highest modal dispersion.Step-index multimode
ECE Board Exam November 1997Calculate the energy of the photon of infrared light intensity at 1.55 um.
ECE Board Exam November 1996The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted is known as __________.mode
ECE Board Exam March 1996An absorption loss caused by valence electrons in the siica material from which fibers are manufactured.Ultraviolet absorption
ECE Board Exam April 2001Which of the following is not a major component of an optical time domain reflectometer used in fiber optic communication?vertical and horizontal plates
-------------------- major component of an optical time domain reflectometer used in fiber optic
communication---------------------LaserBeam splitterPulse generator
ECE Board Exam November 2000Which of the following is a part of an optical time domain reflectometer?Beam splitter
ECE Board Exam April 2000This refers to a certain material which is most sensitive to light.Photoresist
ECE Board Exam November 1999Referred to as a light source of fiber optic which supplies level of 5to 7 milliwats and having a narrow spectrum of emission.Injection laser diode
ECE Board Exam April 1999Most likely, how many times would a fiber optic break in a span of thirty years?2 - 3 times
ECE Board Exam November 1998An advantage of optic fiber rejecting an induced noise signal from magnetic field or solar storm fluxImmunity to noise
ECE Board Exam April 1998Which of the following colors of light rays has the shortest wavelength?Violet
ECE Board Exam April 1997Fiber optic cable operates near ________ frequencies.800 THz
ECE Board Exam November 1997If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time?
ECE. Board Exam November 1996Proposed the used of a clad glass fiber as a dielectric waveguideBockham and Kao
ECE Board Exam November 2000ln electronic communications where fiber optic material is used, a reflectedwave is a possibility. what happen to the polarization of this reflected wavewhen compared to its original form?Shifts to 180 degrees
ECE Board Exam April 2000The effect of multimode propagation caused the rays leaving the fiber tointerfere constructively and destructively as they leave the end of the fiberthis effect is called _________.modal delay spreading
ECE Board Exam November 1999 What is the wavelength for deep violet light?500 nmeter
ECE Board Exam April 1999A device in the fiber optic that is used to attenuate the reflected signal from the polished end of the fiber which has a possibility of developing into a noise.Isolator
ECE Board Exam November 1998One of the advantages of the fiber optic which is referred to the volume of capacity of signals it can carryBandwidth
ECE Board Exam April 1998Circuit used to amplify the optical signal in fiber optics communications links.Optical repeater
ECE Board Exam November 1997A device that reduces the intensity of light in fiber optics communication systemsOptical attenuator
ECE Board Exam April 1997Lifetime of ILDs50.000 h
ECE Board Exam November 1996What is the stage of the sand becoming a silicon?Molten
ECE Board Exam November 2000One of the major limitations of a plastic fiberoptic used in communicationDue to its high losses
ECE Board Exam April 2000One of following is considered the largest source of signal power loss in theuse of fiber optic as communications medium such as due to misalignment.ConnectionECE Board Exam NOvember 1999One of the following is related to the application of solid material as a medium where light travels.medium where Ilght travels. apphcatlon of 5DHd mater-ja}; as 3Fiber optics
ECE Board Exam April 1999Which of the following is not considered as one of the causes for the loss of signal power as light travels through a fiber optic?Inter-modulation----------------causes for the loss of signal power as light travels through a fiber optic-----------------ScatteringFiber bendingAbsorption
ECE Board Exam November 1997The core of the optical fiber has _______a higher index of refraction than the cladding
ECE Board Exam November 1997Loss due to the diffraction of light when it strikes on the irregularities formedduring the manufacturing process of the fiber optics.Rayleigh scattering loss
ECE Board Exam November 1996If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time?
ECE Board Exam November 2000A phenomenon which causes the speed of light rays propagation in the fibermaterial changes, as it passes through different medium in the fiberRefraction
ECE Board Exam April 2000At what intenial does a fiber optic needs a repeater in communicationssystem?30 to 300 miles
ECE Board Eanm November 1999Referfeq to as a limit in reducing further the loss of signal passing through afiber optic caused by scattering.Rayleigh effect
ECE Board Exam April 1999These are band of light wavelengths, that are too short to be seen by the human eye.Ultraviolet
ECE Board Exam November 1998A quarter wavelength device made of crystalline calcite that changes polarization in the optic fiber communicationRetarder
ECE Board Exam April 1999At what power levels does fiber optic have when used in electronic communications?Range of micro to milliwatts
ECE Board Exam November 1998One of the following is among the types of fiber optics used in electronics communication.Semi-graded multimode
ECE Board Exam November 1998How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic?By application of antireflection coating ECE Board Exam November 1998What is the device use in used in fiber optic communication which consist of a receiver transmitter use tc clean up and amplify digital data moving in one direction and another in opposite direction? Optic regenerator
ECE Board Exam November 2000An advantage of fiber optic over co-axial cable as a result of coupling signalsfrom one to the other due to changing magnetic field in one or both.Crosstalk
ECE Board Exam April 2001What is the index of refraction of a certain substance if light travels throughthe substance at 100 meters at a time is to 140 meters to air'?
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Saturday, August 6, 2011
OPTICAL FIBER TRANSMISSION MEDIA (C13 Tomasi)
CHAPTER 13OPTICAL FIBER TRANSMISSION MEDIA
1)Uses light as a carrier of information.Optical communications system
2)Electronic communications system is directly proportional to bandwidth.Information-carrying capacity
3)Bandwidth of an analog communications system as a percentage of its carrier frequency.bandwidth utilization ratio
4)Device constructed from mirrors and selenium detectors that transmitted sound waves over a beam of light.Photophone
5)Experimented with an apparatus called photophone.Alexander Graham Bell
6)Used extensively in medical field.Flexible fiberscope
7)Invented in 1960.Laser (light amplification by stimulated emission of radiation)
8)Advantages of Optical Fiber cables.
1. wider bandwidth and greater information capacity2.immunity to crosstalk3. immunity to statistic interference4. environmental immunity5. safety and convenience6. lower transmission loss7. security8. durability and reliability9. economics
9)Disadvantages of Optical Fiber cables.1. interfacing cost2. strength3. remote electrical power4. optical fiber cables aremore susceptible to losses introduced by bending the cable5. specialized tools, equipment, and training
10)Reduces the possibility of the occurrence of a detrimental phenomenon.Stress corrosion
12)Protective coating.Buffer jacket
14)Increases the tensile strength of the over all cable assembly.Strength member
15)Process of decaying from one energy level to another energy level.Spontaneous decay or spontaneous emission
16)Science of measuring only light waves that are visible to human eye.Photometry
17)Measures the rate at which electromagnetic waves transfer light energy.Optical power
18)Spectral separation of white light.Prismatic refraction
19)Simply the ratio of velocity of propagation of a light ray in free space to the velocity of propagation of a light ray in a given material.Refractive index
20)Angle at which the propagating ray strikes the interface with respect to the normal.Angle of incidence
21)Angle formed between the propagating ray and the normal after the ray has entered the second medium.Angle of refraction
22)Closely related to acceptance angle and is the figure of merit commonly used to measure the magnitude of the acceptance angle.Numerical aperture
23)Simply means path.Mode
24)More than one path.Multimode
26)Probably the most important characteristic of the cable.Power loss
27)Three factors that contribute to the absorption losses in optical fibers:1. ultra violet absorption2. infrared absorption3. ion resonance absorption
28)Caused mainly by small bends and kinks in the fiber.Radiation losses
29)Caused by excessive pressure and tension and generally occur when fibers are bent during handling or installation.Contants-radius bends
30)Caused by the difference in the propagation times of light rays that take different path down a fiber.Modal dispersion
32)A p-n junction made from two different mixtures of the same types of atom.Mojunction structure
33)Generally constructed of silicon-doped gallium-arsenide.Epitaxially grown
34)Homojunction LED’s output approximately 500 μ at a wavelength of 900 nm.Planar diffused
35) Advantages of heterojunction devices over homojunction devices;
1. increase in current density generates a more brilliant light spot.2. smaller emitting area makes it easier to couple its emitted light into a fiber.3. small effective area has a smaller capacitance, which allows the planar heterojunction LED to be used at a higher speed.
36)Depletion-layer photo diode and is probably the most common device used as a light detector in fiber optic communications system.PIN diode
37)Characteristic of a light detector.1. responsivity2. dark currents3. transit time4. spectral response5. light sensitivity0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Fiber Optics, Tomasi, Transmission Lines
Tuesday, May 3, 2011
Fiber-Optic Systems (Blake C25)
Chapter 25: Fiber-Optic Systems
TRUE/FALSE
1. Most new telephone trunk cables are fiber-optic.
ANS: T
2. Cable TV systems use fiber-optic cable.
ANS: T
3. Many data network cables are fiber-optic.
ANS: T
4. Fiber-optic cable is not practical for telephone trunk cables.
ANS: F
5. CATV uses analog modulation on fiber-optic cables.
ANS: T
6. Usually, splicing losses can be disregarded in loss-budget calculations.
ANS: F
7. The rise time of a transmitter limits its bandwidth.
ANS: T
8. RZ encoding allows twice as much pulse spreading as NRZ.
ANS: F
9. The product of bandwidth times distance describes dispersion in a multimode fiber-optic cable.
ANS: T
10. Regenerative repeaters for fiber-optic cables typically convert the light signal to an electrical signal, and then back to light.
ANS: T
11. Optical amplifiers are not suitable for digital signals.
ANS: F
12. Dispersion effects accumulate when optical amplifiers are used.
ANS: T
13. Most fiber-optic systems use TDM.
ANS: T
14. Fiber-optic cables shorter than 100 km typically do not require repeaters.
ANS: T
15. SONET operates at a base speed of 25 Mbps.
ANS: F
16. SONET solves many of the timing problems in synchronizing digital signals.
ANS: T
17. SONET is typically used on LANs.
ANS: F
18. FDDI can be used on a LAN.
ANS: T
19. Soliton pulses can travel down a fiber-optic cable with no dispersion.
ANS: T
20. TDR cannot be used on fiber-optic cables.
ANS: F
MULTIPLE CHOICE
1. FDDI stands for:a. Fiber Digital Data Interface c. Fiber Distribution Delay Interfaceb. Fiber Distributed Data Interface d. Frequency-Division Data Interface
ANS: B
2. FITL stands for:a. Fiber In The Loop c. Frequency Input to The Loopb. Fiber Input Timing Loss d. Fiber Input Timing Loop
ANS: A
3. FTTC stands for:a. Fiber Transmission Timing Constraintb. Fiber Transmission Technology Committeec. Fiber Telephone Transmission Cabled. Fiber To The Curb
ANS: D
4. SONET stands for:a. Simple Optical Network c. Synchronous Optical Network
b. Standard Optical Network d. none of the above
ANS: C
5. DWDM stands for:a. Digital Wavelength-Division Modulationb. Dense Wavelength-Division Modulationc. Double Wavelength-Division Modulationd. Dense Wavelength-Division Multiplexing
ANS: D
6. A Soliton is a:a. defect in the glass c. type of pulseb. type of particle d. type of optical network
ANS: C
7. Adding bits to synchronize one digital signal to another is called:a. bit stuffing c. SDHb. bit-synch d. WDM
ANS: A
8. Power above the minimum required by an optical receiver is called:a. gain margin c. excess gainb. system margin d. overdrive
ANS: B
9. Typically, repeaters are not required for fiber-optic cable lengths up to:a. 1000 miles c. 100 kmb. 100 miles d. 10 km
ANS: C
10. In SONET, OC-1 stands for:a. Optical Carrier level one c. Optical Channel oneb. Optical Coupler unidirectional d. Optical Cable type 1
ANS: A
11. In SONET, STS stands for:a. Synchronous Transport Signal c. Synchronous Transmission Signalb. Synchronous Transport System d. Synchronous Transmission System
ANS: A
12. A commonly used fiber-based system for LANs is:a. FDDI c. gigabit Ethernetb. high-speed Ethernet d. all of the above
ANS: D
13. The use of solitons on fiber-optic cables is:a. common c. obsoleteb. experimental d. not possible
ANS: B
14. OTDR stands for:a. Optical Time-Delay Response c. Optical Time-Domain Reflectometerb. Optical Timing Delay Requirement d. Optical Time-Division Relay
ANS: C
15. Using fiber-optic cable in a telephone system except for the connection to the subscriber's phone is called:a. FDDI c. FITLb. FTTC d. SONET
ANS: B
COMPLETION
1. FTTC stands for Fiber To The ____________________.
ANS: Curb
2. FITL stands for Fiber In The ____________________.
ANS: Loop
3. SDH stands for Synchronous Data ____________________.
ANS: Hierarchy
4. WDM stands for ____________________-division multiplexing.
ANS: Wavelength
5. SONET stands for ____________________ Optical Network.
ANS: Synchronous
6. FDDI stands for Fiber ____________________ Data Interface.
ANS: Distributed
7. Optical amplifiers use ____________________-doped glass.
ANS: erbium
8. Optical amplifiers use a ____________________ laser.
ANS: pump
9. Dense ____________________ allows many different wavelengths of light to share a cable.
ANS: WDM
10. The OC-1 line rate is ____________________ Mbps.
ANS: 51.84
11. SONET does not use bit ____________________ to synchronize two digital signals.
ANS: stuffing
12. SONET uses a ____________________ to denote the starting position of an information frame.
ANS: pointer
13. FDDI systems use two ____________________ rings to carry signals.
ANS: token
14. The two rings of an FDDI system carry data in ____________________ directions.
ANS: opposite
15. Each ____________________ in an FDDI system acts as a regenerative repeater.
ANS: node
16. FDDI uses ____________________ mode cables.
ANS: multi
17. The data rate of an FDDI system is ____________________ bps.
ANS: 100 M
18. SONET frames have considerably more ____________________ than do DS frames for information about signal routing and setup.
ANS: overhead
19. The number of bytes in a SONET frame is ____________________.
ANS: 810
20. The number of bytes in the payload of a SONET frame is ____________________.
ANS: 774
21. The number of rows in a SONET frame is ____________________.
ANS: 9
22. The total number of overhead bytes in a SONET frame row is ____________________.
ANS: 4
23. The number of path overhead bytes in a SONET frame row is ____________________.
ANS: 1
24. SONET frame rows contain path overhead and ____________________ overhead.
ANS: transport
25. In SONET, SPE stands for synchronous payload ____________________.
ANS: envelope
SHORT ANSWER
1. What is the bandwidth of a first-order LPF with a rise time of 350 nanoseconds?
ANS: 1 MHz
2. Calculate the total rise time for a fiber-optic system if the transmitter, receiver, and cable each have a rise time of 50 nanoseconds.
ANS: 86.6 nanoseconds
FILTERS…
CHAPTER 15 ACTIVE FILTERS
CHAPTER 15 ACTIVE FILTERS
1. The ___________ of a band-pass filter is the ratio of the center frequency to the bandwidth. Quality factor
2. An active filter category that rejects the frequencies within a certain bandwidth and passes frequencies outside the bandwidth Band-stop filter
3. A filter response characteristic that provides a very flat amplitude response in the passband and a roll-off rate of -20dB/decade/pole Butterworth characteristic
4. Each filter in a cascaded arrangement is called ___________. Stage or section
5. It is one of the most common configurations for two-pole filter. It is also known as a voltage-controlled voltage source filter. Sallen-Key
6. A filter required to get a third-order low-pass response. This is done by cascading a two-pole Sallen-key low-pass filter and a single-pole low-pass filter Three-pole filter
7. Each additional filter in a cascaded arrangement adds _______dB to the roll-off rate -20 dB
8. The rate of decrease in gain, below or above the critical frequencies of a filter. Roll-off
9. Technology that enables the tracking and/or identification of objects. Radio Frequency Identification (RFID)
10. Four categories of active filters Low-pass, high-pass, band-pass, and band-stop
11. Low-pass bandwidth is equal to Cutoff frequency
12. Filters with the Bessel characteristic are used for filtering ________ waveforms Pulse
13. Two common types of band-stop filters. Multiple-feedback and state-variable
14. Tiny, very thin microchips with memory and a coil antenna RFID tags
15. This type of tag does not require batteries. The tag is inactive until powered by the energy from the electromagnetic field of an RFID reader Passive RFID tag
16. This type of tag is powered by a battery and is capable of communicating up to 100ft. Or more from the RFID reader. Active RFID tag
17. Another type of tag that is a paper labelled with printing with the RF circuitry and antenna embedded in it. Smart label
18. The property of selecting signals with certain selected frequencies while rejecting signals with other frequencies. Selectivity
19. A pole is simply a circuit with how many resistor or capacitor? 1
20. The damping factor affects the filter response by negative feedback action. True/false
True
21. The more poles a filter has , the faster its roll-off rate is True
22. Another term for state-variable filter Universal active filter
23. Two methods of determining a filter’s response by measurement Discrete point measurement and swept frequency measurement
24. Produces a constant amplitude output signal whose frequency increases linearly between two preset limits. Swept frequency generator
25. How many poles does a Sallen-Key high pass filter have? 2
26. The center frequency of a state variable resistor is set by the _______ circuits in both integrators, RC
GEAS…
CHEM 101 (EDGE)
Electron was discovered by A.J.J. Thompson
The isotopes of an element differ in the number of Neutrons
Atoms or ions which have the same electronic configurationIsoelectronic
Which group in the periodic table is known as the alkali metals.Group 1
Which group in the periodic table is known as the halogens. Group 7
Which group in the periodic table is known as the alkaline earth metals. Group 2
Which group in the periodic table is known as the noble gases.
Group 8
The components resulting from a reaction is called Products
What kind of chemical bond will form in a binary compound where the elctronegativity difference between atoms is less than 1.5Covalent bond Compounds which only contain carbon and hydrogen are called Hydrocarbon
Which of the following designation means that the amount of solute is expressed in physical mass units, i.e. grams and the amount of solution is expressed in volume units, i.e. milliliters w/v
What kind of chemical bond will form in a binary compound where the elctronegativity difference between atoms is greater than 2.0 Ionic bond
The isotope of hydrogen Protium, Tritium, Deuterium
The isotope of hydrogen with only one neutronTritium
The atoms having different atomic number but the same mass number are called Isobars
What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is less than 1.5?Covalent bond
The element which has a mass of about 9 amu is beryllium (Be), atomic number 4. What is the charge on the Be atom?Neutral
The mass of an alpha particle is how many times more than that of an electron7300
Atoms with the same number of protons but different number of neutrons are calledIsotopes
The forces that hold atoms together are calledChemical bond
An atom or group of atoms that has a net positive or negative charge is called
Ion
A positive ion is called Cation
A negative ion is called Anion
The force of attraction between oppositely charged ions is calledIonic bonding
The horizontal arrangement of elements of increasing atomic number in a periodic table is called Period
The vertical arrangement of elements of in a periodic table is called Group
If the number of gas molecule is doubled in a certain volume of gas, the pressure Is doubled
A symbolic representation to emphasize the valence shell of an atom is called Electron dot diagram
For which elements does the number of electrons in their outer or valence shelll correspond to their group number Representative or main group
What is the maximum number of electrons that can fit in a “p” orbital 5
The property of liquid which describes their resistance to flow is called Viscosity
The anions and cations which are unaffected by the reaction in solution are called Spectator ions
A reaction in which heat is produced is calledExothermic
The atoms having different mass number but the same number of neutrons are called IsotonesRutherford model of an atom failed to explain The position of proton and neutrons
The concept that electrons revolve around the nucleus in specific paths called orbits or energy levels was proposed by
Niels Bohr
The number of atoms present in 6.023 x 10^23 12 grams of carbon-12 is called Avogadro’s constant
An instrument that separates particles of different isotopic composition and measure their individual relative masses.Mass spectrometer
These are compounds containing water molecules loosely bound to the other components.Hydrates
If a more active element replaces a less active one in a compound, the reaction is: Replacement reactions
If a single reactant is transformed by heat or electricity into two or more products, the type of reaction is:Decomposition
The numerical value for standard pressure of any gas is:760 mm Hg
Any process of extracting the metal in a fused state is calledSmelting
Which of the following does not change with change in temperature?Mass
A device used to measure density.Hydrometer
The statement “mass is neither created nor destroyed in a chemical reaction” is known as:The law of conservation of mass
What kind of chemical bond will form in binary compounds where the electronegativity difference between atoms is greater than 2.0Ionic bond
A reaction in which heat is absorbed is called Endothermic
In redox reaction, the component supplying the electrons is called the Reductant
In redox reaction, the component receiving the electrons is called the
OxidantA covalent bond formed by the combination of collinear p orbitals is also called a Sigma bond
The central part of an atom is called Nucleus
The mass of a proton is about how many times that of an electron 1837
The particles in the nucleus, namely the neutrons and the protons are collectively referred to as Nucleons
The number of orbiting electron is normally _____ the number of the protons in the nucleus of an atom Equal
The chemical formula which shows the relative number of atoms of all the elements present in a compound is called the Empirical formula
The chemical formula which shows the exact number of atoms of all the elements present in a compound is called the Molecular formula
When an atom loses an electron it forms Cation
When an atom gains an electron it forms AnionThe maximum number of electrons that the first energy level can accommodate is 2
The X-rays are discovered by W.C. Roentgen
Refers to atoms or ions, which have the same electronic configuration.Isoelectronic
Which group of the periodic table is known as the akali metals?Group I
Which group is known as the halogens?Group VII
The horizontal arrangement of elements increasing atomic number in a periodic table is called:
Period
The number of protons in the nucleus of an atom is called Atomic number
The measure of the resistance of an object to a change in its state of motion is called Inertia
Refers to agreement of a particular value with the true value Precision
Refers to the degree of agreement among several measurements of the same quantity Accuracy
A property of matter often used by chemist as an “identification number” for a substance Density
Protons and neutrons can be broken down further into elementary particles called Quarks
The principle of constant composition of compound, originally called “Proust’s Law” is now known as Law of definite proportion
The mass that enters into a chemical reaction remains the unchanged as a result of the reaction. In precise form: mass is neither created nor destroyed. This is known as:The law of conservation of mass
When the same elements can form two different compounds, the ratio of masses of one of the elements in the two compounds is a small whole number relative to a given mass of the other elements. This is known as:The law of multiple proportion
The ratio of the density of the test liquid to the density of the reference liquid is called Specific gravity
How many electrons are there in a covalent bond? 2 SI unit of temperature Kelvin
The elements that a compound is composed of is present in fixed and precise proportion by mass. This is known as Law of constant composition
The mass to the nearest atomic-mass unit of an atom which contains 9 protons and 10 neutrons
19 amu
The net electric charge of any atom is 0
The tendency of atoms to attract electrons into their valence shells to form anions is described by the concept of Electron affinity
The tendency of atoms to attract electrons shared in a covalent bond is called Electronegativity
A covalent bond between atoms of identical electronegativity is called Nonpolar
A formula which describes only the number of each element in the molecule is called the Molecular formula
The formula which shows how atoms are joined together is called the Structural formula
The pairs of electrons not shared in the covalent bond are called Nonbonded electrons or lone pair
The word atom comes from the Greek word ”atomos” meaning Cannot be cut
Under normal state an atom is said to be Electrically neutral
The word electron comes from the Greek word ”elektron” meaning Amber
The word proton comes from the Greek word ”proteios” meaning Of first importance
A solid which has no crystalline structure is called Amorphous
A chemical substance which readily evaporates and readily diffuses at ordinary room temperature and pressure conditions is called Volatile
Which of the following falls under fluids Both liquid and gas
The gases that rarely take part in a chemical reaction are called Noble gases
Which type of ions, metals form when enter into a chemical reaction Positive ions
The chemical name for baking soda Sodium bicarbonate
The subatomic particle with a negative charge and mass of 9.1 x 10^ -31 kg is Electron
The subatomic particle with a positive charge of mass 1.6 x 10 -27 kg is Proton
Neutron was discovered by Chadwick1 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: EDGE, GEAS
Tuesday, October 18, 2011
GEAS 1
Employee's perception on the probability that he or she gets what he/she expectsExpectancy Theory
The type of leadership appropriate when manning professionalsfree rein leadership
"A satisified employee is motivated from within and a dissatisified employee is not motivated"Herzberg's Two-factor theory
The kind of authority usually given to budgets officers in the organizationfunctional authority
The type of organization for small firmsfunctional organization
The process that focuses on how subunits can use allocated resourcesintermediate planning
The type of reward that includes money, promotion..extrinsic reward
types of rewardsextrinsic or intrinsic
The type of power in the people of higher position towards those in the lower position in the organizational heirarchylegitimate power
Measure the ability to learnaptitude test
The type of control when the engineer manager collects data on a completed task, and evaluation,comments, and suggestions on how to improve the taskfeedback control
Temperature unchanged, The pressure of an ideal gas is inversely proportional to its volumeboyle's law
The rankine value that refers to the absolute temperature460 degrees Fahrenheit ( alam ko negative to.. please check sa notes )
The average kinetic energy of a gas is directly proportional to itsabsolute temperature
according to the modern view of the atomic modelelectron cloud..
the quantum number that refers to the spin of the electronspin quantum number
permeability is slightly greater than 1aluminum
Used in DNA making?zinc
Used to make galvanized ironzinc
most common metal mixed with copperzinc
the first law of thermodynamics is also calledlaw of conservation of energy
states that the amount of heat that is converted into heat is dependent on the temperature where it takes place
second law of thermodynamics
the process in which a highly energetic particle transfers energy to an adjacent less energetic particleconduction
emission of electromagnetic waves or photonsradiation
a device that transfers heat between fluids without mixing the twoheat exchanger
Ideal Gas Constant8.314 kJ per kmol-K
Series of changes or processes in the system that repeatsCYCLE
At standard temperature and pressure, the volume of 1 mol isSAME FOR ALL PERFECT GASSES.
Reluctance of an object to change its state of rest or its uniform motionINERTIA
1 slug14.6 kg.
1 lb4.45 Newtons
The law of reaction - "For every force that acts on one body, there is a second force equal in magnitude but opposite in direction that acts upon another body."Third law of Motion
The law of acceleration - " Whenever a net resultant force acts on a body, it produces an acceleration in the direction of the resultant force that is directly proportional to the resultant foce and inversely propoportional to the mass of the body."Second law of Motion
The law of inertia - "There is no change in the motion of the body unless an unbalanced external force is acting upon it."First law of Motion
pHPositive Hydrogen ion
pH 1 to 6Acid
Mass of electrons in grams9.107 times 10 to the -28
Mass of protons in grams1.672 times 10 to the -24
Mass of neutron in grams1.675 times 10 to the -24
Charge of electron negative1.602 times 10 to the -19
charge of proton1.602 times 10 to the -19
Charge of neutron0
The mass of the neutron is approximately 1,839 times greater than electrons1839
The mass of the proton is approximately 1,836 times greater than electrons1836
Top 3 conductorSilver, Copper, Gold
least conductornichrome
atomsbuilding blocks of engineering materials
Aluminummost abundant metal in earth
Ductilityratio of ultimate shear to yielding stress
period thetime taken by a body in uniform motion to travel an orbit
760 torr equal to
1 ATM
Charle's LawConstant Pressure, Variable Temperature and Volume
Twice amplitudetwice maximum velocity
R.A. 8792Philippine Electronic Commerce Act or E-Commerce Act
each orbital has 1 electron placed in it before pairing of electron in orbitals occursHunds' Rule
angular speed (momentum)Spin Quantum #
resistance(internal friction) of fluids to flowviscosity
S.I. unit of pressure Newton per square meterPascal
losses due to friction in oscillationdamped oscillator
cohesive attraction that causes liquid to minimize its surface areasurface tension
Maximum stress before permanent deformationelastic limit
also known as modulus of rigidityshear modulus
thermodynamic propertiesvolume, pressure, temperature
defined as mass per unit volume. Independent of size and shapedensity
another term for specific gravityweight density
ability of metal to be permanently deformedductility
elastic modulus applicable to liquidsbulk modulus
Combine two small elementsfussion
Larger element divided into 2 smaller elements…Fission
object subjected to equal and opposite forces on different lines of direction is said to be undershear stress
unit of mechanical shearjoule
conduction bandwhere free electrons move
gives off a yellow green appearanceChlorine
Gives off blue-black-violet colorIodine
young's modulus is also known asmodulus of elasticity
stress at which a material begins to plastically deformyield strength
irregularity within a crystal structureDislocation
most common defect of crystalLine defect
What is the S I unit of momentum kg. meter per sec.Kg-m / s
What is the S I unit of impulse Newton - sec.N-s
total momentum of a closed system is constantConservation of linear momentum
number of cycles as a result of timeperiod
A common copper alloyZinc
a solution that is a liquid conductorelectrolyte
determines the acidity or basePH measurement
what is PH 7neutral
delegation of authorityassigning of different degrees of authority
Vander Waals bondingConnection between crystal atoms / forms eight pairs of electrons when bonded
Covalent bondingaggregate less when near each other than when separated from one another
metallic bondinginteraction of ionic lattice and electron gas
electrostaticbonding bonding between positive and negative charges
atomic numberelement identity
spin quantumdirection
Elementa pure substance that cannot be broken down by chemical means to a simpler substance.
Valence Electronsdetermines the ability of atoms to combine with other atoms.
Nitrogen GroupV - A
Electronics Engineer appearnce fee per hour
500
Electronics engineer retainer's fee1500
maximum allowable exposure to radiation from an electronic equipment must not exceed to, 100 ms
keystone of professional conductintegrity
Requiring the services of a duly licenced ECE… planning, designing…Department Order No. 88
law provides for the regulation of radio station, communications in the Phils.R.A. 3846
policy to improve the provision of Local Exchange carrier serviceE.O 109
Foundation of Moral philosophyJustice, Honesty and Courtesy
Philippines is under what region in terms of frequency allocationRegion 3
Data network operated by enfranchised telecommunications carrier that is authorized to provide data.Public Switched Data Network
An ECE board member must be a citizen & resident of the Philippine for at least, BLANK, consecutive years prior to his appointmnt5 Years
Testing and quality control of electronics productManufacturing
If the engineer approves that a certain electronic product were according to engineering standard..( something like this )Acceptance
Implementing rules and regulations ( IRR ) of R.A 9292August 31, 2007
Electronic Commerce Act of 2000R.A. 8792
VOIP service provider performance bond5 million
The certificate of Authority issued by NTC to A CATV maximum term.15 years
Maximum effective radiated power in Metro Manila and Metro Cebu for Channels 7 - 131000 Kw
Metro Manila Commercial load in radio stations15 minutes
Minimum carrier power output of a Standard AM Broadcast … direct supervision of an Electronics engineer is required1 Kw
Maximum power allocation for AM broadcast in Metro Manila50 kW
at what temperature does a magnetic material loses its ferromagnetic propertiesCurie Temperature
Specific Gravity also termed asRelative Density
Moment of Inertia is dependent onMass, Axis of rotation, Size and Shape
diatonic scale with added 5 half tonesChromatic Scale
binds the protons and neutrons together in the nucleus of an atomexchange force
depend on the number of harmonics present…Quality of Sound
Avogadros Number 6.022 x 10 to the ___ power23rd
controlled testing of the properties of a substance or system through carefully recorded measurements Experiment
father of scientific method
Galileo
number of S.I. base units7
Father of Modern ChemistryAntoine Lavoissier
means indivisibleAtomos
Pressure held constald, Volume of gas is inversely proportional to volumeCharles Law
Naming Chemical CompoundsChemical Nomenclature
Best Conductor of ElectricitySilver
Denser metal settles on less denseFloatation
the closeness of two sets of measured group of valuesPrecision
bending of a strip of metalElastisity of Flexion
twisting of springElasticity of Torsion
Acid and base balancedNeutralization
lacking of mass over something…Mass defect
where fission is controlledNuclear Reactor
operating at low temperatureCryogenics
what property of plastic changes with heat distortionMechanical
increasing in the small diameter tube with fluidCapillarity
Relating 2 different volume / densityRelative Humidity
Speech density… “volume”Absolute Humidity
Density of material with respect to density of airSpecific humidity
Same/Like materialsCohesion
Different/Unlike materialsAdhesion
Necessary nuclear reactor (uranium)Critical Size
RadioactivityCurie
Flow of fluid in pipe; “pressure”Bernoulli principle
“atomic mass”Physicists atomic weight
High production, something will limitLaw of diminishing return
Mix different quantities of some elementLaw of multiple proportion
Indistinguishable liquid and gasCritical Point
Constant angular momentum, increasing kinetic energyKepler’s Law
Light actually passes throughReal image
Light seemed to pass throughVirtual image
Capital mobile dealerP 100,000
“Defect of lens”, “Rays near the edge”Spherical Aberration
“comet-shaped”coma
“Differences in vertical and horizontal distance”Astigmatism
Unit of electrostatic chargeStatvolt
SI unit of potential differencevolt
Electrostatic measuring device?Leaf electroscope
Class B FM500 ft.
Primary FM stations allowed of how many translators2
Acids formed from weak bases dissolved in H2OHydrolysis
Matter can be broken downDemocritus
Property of gas equals individual propertyGibb’s Theorem
NeutronChadwick
Summary observed factScientific Law
Partial volume
Azamat's Theorem
Liquid not used as solvent in a chromatographyWater
Not an ionization BondC6H12O6
1 molecule enters an orbit, spread, about atom spinHund’s rule of multiplicity
AM primetime6:00 AM – 8:00 PM
Change of temp w/o change of phaseSensible Heat
“oil or mining” / nauubos na resourcesDepletion Cost
Penetrate;moleculesDiffusion
Quantitative measurementStoichiometry
Shield for x-rayLead
(ratio of something to air to e)Absolute Index of Refraction
Incident angle is greater than critical angleTotal Reflection
Temperature, konting pressure na lang solid to liquid naCritical Temperature
Removal of EnergyWater to ice
Separation of liquid through because of difference in its boiling pointsDistillation
1 dyne on separation of 1 cm1 stat coloumb
Non performance that results in the injured party receiving something substantially less than or different from what the contract is intended.Material Breach
1 Joule10 raise to 7 ergs 10^7
ability to be mixed with otherMiscibility
Used as solute in stainless steel ( to prevent "kalawang" hehehe )Chromium
Used a slovent in stainless steelIron
Perfect absorberBlack Body
ratio of velocities before and after an impactcoefficient of restitution
Temperature where degree C = degree Fahrenheit- 40degrees
Used in Vehicle BaterriesSulfuric Acid
Medium… travels fast at zero degrees ( 0 deg C)Glass
Something about Bouyancy of material to waterArchimedes Theory
heat exceeds saturation at less pressureSuperheated
second most abundant element on earthoxygen
energy gap of GaAs1.43 V 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: GEAS, Notes
Wednesday, October 5, 2011
GEAS
GEAS Mechanical energy of pressure transferred into energy of heatAns. enthalpy
For a common microscope the image formed by the eyepiece isAns. inverted
Added to nucleus of an atom without changing its chemical propertiesAns. alpha particle
Ester of glycerol with unsaturated fatty acidsAns. oils
Energy of an electron is assumed to be zero whenAns. it is far away from the nucleus
Chief ore of zincAns. Sphalerite
Punitive damageAns. Exemplary damage
Functional depreciationAns. obsolescence
Maritime communication lawAns. R.A. 3396
Brightness of light sourceAns. luminous intensity
Heated metal(hot bodies)Ans. Edison effect
Producer gas is a mixture of nitrogenAns. carbon monoxide
1BTUAns. 1054 Joules
ParamagneticAns. Chromium
How an element is connected to otherAns. Structural formula
Arrangement of atoms in a moleculeAns. affects the reactivity of molecules
False statementAns. convex mirror can be used as main objective in a reflecting telescope
Average decay timeAns. mean life
Weightless environment, attach a ball to a spring and spin, the acceleration vector of the ball isAns. always point inward towards you
Change a sample of solid to liquidAns. heat of fusion
Failure to regain its original size and shapeAns. elastic lag
Reciprocal of bulk modulusAns. compressibility
Period driving forceAns. resonance
Willingness of an atom to receive electronsAns. electron affinity
Temperature below the saturation temperature corresponding to its pressureAns. subcooled liquid
Venturimeter measures ___ of waterAns. velocity
Temperature where Joule Thomson effect is zeroAns. inversion
Unit of moment of inertiaAns. kg-m2
Copper alloy used as collectors for electric generatorAns. Tin bronze
Solution of weak acid and its conjugate base, or weak base and its conjugate acidAns. buffer
System remains infinitesimally closed to an equilibrium at all timesAns. quasi-equilibrium
Hydrocarbon contain one or more double bondsAns. alkene
Process of making hydrocarbon gasAns. Bosch
Factor of safetyAns. yielding stress over working stress
Propagate same speed as lightAns. heat wave
Ratio of market price per share to earnings per shareAns. price-earnings ratio
Degrees F equals degrees CAns. -40
Unit of ionization radiationAns. Becquerel
Water is electrolyzedAns. hydrogen and oxygen atoms are separated from each other.
Black lightAns. UV radiation
RetentivityAns. permanent magnet
Mass of atomic particlesAns. mass spectrograph
3G bondAns. 300M
RefrigerantAns. Dimethyl ether
Amount of energy to fracture a given volume of material
Ans. Impact strength
Theory of light emitted in discrete amountAns. Quantum theory
Cast iron hard and wear resistanceAns. white iron
Heat engine can’t transfer heatAn. 2nd law of thermodynamics
Reflected sound waves returnAns. echo
Irregular succession of compression and rarefactionAns. unpitched sound
Luminance of clear skyAns. 3200
Blackbody radiation emitted at freezing platinumAns. candle
Result of atmospheric refractionAns. mirage
Absorbs radiant energy and re emits it in wavelengthsAns. fluorescence
Design to detect radiation emanating from radioactive sourceAns. Quartz-fiber electroscope
Monosodium Glutamate (MSG)Ans. vegetable protein
KwashiorkorAns. lack of protein
DownerAns. seconal
Decay of a neutron to a protonAns. beta particle
Known concentrationAns. standard solution
A pressure measuring device to register the pressure at all timesAns. mercury manometer
Work done is zero.Ans. isometric
Drink salt waterAns. cell shrink
SpeakerAns. 5 CU
DoctoralAns. 45 CU
Gas is produce by the action of sunlight on automobile exhaustAns. ozone
Middle management levelAns. intermediate planning
Process identifying and choosing alternative courses of action in a manner appropriate to the demands of the situationAns. decision-making
Documents that shows proof of legal ownership of a financial securityAns. Coupon
Color that bends the leastAns. red
Series of closets connected by slots or short conduit sleeves between floors or open shaft of the buildingAns. riser shaft
Upon dissociation in water, acid yields hydrogen ions while gases yields hydroxide ionsAns. Arrhenius theory
Friendliest metalAns. Iron0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: GEAS, Notes
Tuesday, October 4, 2011
GENERAL ENGINEERING AND APPLIED SCIENCES
GENERAL ENGINEERING AND APPLIED SCIENCES
Carnot engine when reversed becomes Refrigerator
Highest average translational kinetic energy account to which state of matter Gas
Aluminum is the lightest among the following metals except Magnesium
Alpha particle test charge +2
Strength and machinability Normalizing
Middle C 256Hz
Radioactive source activity Becquerel
The frequency of Middle C 256Hz
Which of the following noble gases is most abundant on earth? Argon
Given mass 1=mass 2=132 lb, distance=1 meter, calculate gravitational force. 2.4 x 10^-7 N
Which of the following is the difference between ground state and excited state of an atom? Electron configuration
Helmholtz free energy is the internal energy of the system ____ Minus the product of entropy and temperature
The escape velocity on earth is 11,200 m/s. What is the escape velocity to the moon? 2,400
The material known as austenite is transformed into bainite when subjected to ___ process. Rapid cooling
Newly SROP provided that devices ___ output power Shall not exceed 25 watts
What is the value of resistivity of aluminum in ohm-m? 2.7 x 10^-8
As stated under D.O.88 for AM broadcasting station, operation sation must be under the supervision of registered ECE if the carrier power exceeds ___ 1kW
What is the unit charge of alpha particle? +2
Sound interference is required in order to attain the phenomenon known as Beats
Aside from platinum, gold, and silver, which is considered as a noble metal? Iridium
What is the velocity of a 100g ball on a 5cm string moving in horizontal circle that requires centripetal force of 1.0N? 2.2m/s
What is the coefficient unit of viscosity? Poise
What is the main characteristic of super__ whose major application are jet engines and gas turbines? Heat resistant
Which ferromagnetic is BCC crystal structure? Iron
What is the force of gravitational attraction between two 132-lb student who are standing 1m apart? 2.4 x 10^-7 N
Which of the following would be different in ground state and excited state upon atom? The electron configuration
Another aspect of pressure and human body is blood pressure. 20/20 vision is ideal…120/80, what is the unit? mmHg
What is the amount of time of activity may delayed without changing the succeeding activity? Slack
One Dalton is equivalent to how many MeV? 931
In alloy nickel is replaced by ___ to produce superinvar alloy. Cobalt
Chart compare planned schedule information to actual. Tracking Gantt Chart
PRC Modernization Act 8981
Type of brass with 85% copper Red brass
What is the ratio of working temperature to the temperature of melting point? Homologous temperature
Type of management that spend most of the time outside Management by wandering
MICROWAVE…
Microwave Communications (Chapter 9: Past Board Excel)
ECE Board Exam April 2001Which of the following will you avoid in the construction of a microwave station?Long horizontal runs
ECE Board Exam November 2000Radio frequency where waveguides are not used extensively.150 MHz
ECE Board Exam April 2000Term used to describe a process of approaching a desired point by directing the vehicle towards that pointHoming
ECE Board Exam November 1999A system which does not refer to a technique in reducing the propagation errors in navigational system such as multipath effectsPulse transmission
ECE Board Exam April 1999Which of the following is a navigational equipment which utilizes a ground radar system to determine the position of a plane during its approach?GCA
ECE Board Exam November 1998_____________ is referred as the difference between available power and power budget.Power margin
ECE Board Exam April 1998Space diversity transmission means transmitting and receiving on __________.two or more antennas operating on the same frequency
ECE Board Exam November 1996One of the reasons why FDM is being replaced by TDM isnoise is amplified with voice when an FDM system is used
ECE Board Exam November 1996What is the baseband frequency of standard FDM basic supergroup?312 to 552 kHz
ECE Board Exam March 1996The k-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to __________4/3
ECE Board Exam March 1996LORAN is navigational system used primarily for _________obtaining your fixed location over a large distances
ECE Board Exam April 2001What navigational system technique uses an antenna directivity to reduce an undesired multipath signals?LORAN-C
ECE Board Exam November 2000In microwave frequencies, the LOS distance is something extended through the occurrence of ____________ducting
ECE Board Exam April 2000Which of the following if not a part of the navigational radar?Duplexer------------- part of navigational radar-----------Pulser
Display unitSynchronizer
ECE Board Exam November 1999How do you account the effect of selective fading on the transmitted signal in terms of its bandwidth?more affirmative at wider bandwidth
ECE Board Exam April 1999Frequencies most affected by knife-edge refraction.VHF and UHF
ECE Board Exam April 1998Refers to an effect of selective fading.A fading effect caused by phase difference between radio wave components of the same transmission, as experienced at the receiving station.
ECE Board Exam November 1996When the clearance above the obstruction is equal to the radii of even Fresnel zones at the point of reflection the RSLis decreased
ECE Board Exam March 1996LORAN is a navigation system used primary forobtaining fixes over large distances
ECE Board Exam November 1966When the value of k increases, the effective result is _______ of the equivalent curvatures.flattening
ECE Board Exam March 1996TACAN is a navigational aid providing _________bearing and distance indication
ECE Board Exam November 1996If Ns = 250 determine the earth radius k-factor.
ECE Board Exam March 1996A one-hop, full duplex, microwave system is in a space diversity arrangement. Determine how many receivers in all are used?2
ECE Board Exam November 1996A microwave communications system space loss calculation formula is92.4 + 20 log F + 20 log D
ECE Board Exam March 1996Radio fading resulting from obstruction losses.Log normal fading
ECE Board Exam April 1998Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna.Circulator
ECE Board Exam November 1996What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path?Frequency
ECE Board Exam November 1996What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz?
ECE Board Exam November 1996Low-power radar usesIMPATT
ECE Board Exam November 2000A component of a microwave station that samples signal traveling in one direction down to the transmission line.Directional coupler
ECE Board Exam April 2000A navigational error which is caused by reflection of obstruction close to the location of navigational aid having a normal concern on directional bearing.Site error
ECE Board Exam April 1999An aircraft deviation measured by an ILS localizer.Horizontal
ECE Board Exam April 1998Which of the following systems is not used in radio detection and ranging?Amplitude modulation
----------- systems used in radio detection and ranging----------Frequency shiftFrequency modulationPulse radar
ECE Board Exam April 1997A microwave system that requires the use of repeater.Intervening system that requires the use of repeater.Distances involved are greater
ECE Board Exam November 1996Space diversity transmission means transmitting and receiving ontwo or more antennas operating on the same frequencies
ECE Board Exam April 1997RADAR meansRadio Detection and Ranging
ECE Board Exam November 2000Which band in the radio spectrum does the radio navigational system Omega transmit?VLF
ECE Board Exam November 1998Which of the following is not a common microwave application?Mobile radio
------------- common microwave application --------------RadarData transmissionSpace communications
ECE Board Exam April 1998What do you call a circuit that controls the magnetron output?Modulator
ECE Board Exam April 1997A microwave link between the earth station and the down-town terminalTerrestrial link
ECE Board Exam November 1997Two or more antennas separated by 9 wavelengths are used.Space diversity
ECE Board Exam April 2000In radio navigation, one of the following deviations of an airplane is determined by an ILS localizer.Horizontal
ECE Board Exam April 1997The advantage of periscope antenna in microwave.
Shorten waveguide link
ECE Board Exam April 2000In navigational system, one of the following indication is provided by the localizer unit of the ILS.A horizontal deviation of an airpalne from its optimum path of descent along the axis of the runway.
ECE Board Exam April 1999Referred to as the cycle time difference between the master and the slave signals to reach the receiver in the operation of loran navigational equipment.Time delay
ECE Board Exam April 1999Which of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?Weak part
ECE Board Exam April 1999What is being measured in radar theory to complete the determination of a distance to a target or object, after a high radio frequency signal is transmitted to a target?Echo time off the object to the source
MODULATION…
Modulation 2/2 (C3 Past board : excel)
CONTINUATION.....
ECE Board Exam April 1997Modulation meansvarying of some parameters of a carrier such as its amplitude to transmit information.
ECE Board Exam November 1996Which of the following is not a baseband signal of modulation?RF carrier
ECE Board Exam April 2001Which of the following components is used to produce AM at very high frequencies?PIN diode:
ECE Board Exam November 1999A process which occurs in the transmitter part of the transceiver.Modulation
ECE Board Exam April 1999In radio rules and regulation, the extremely high frequency band is referred to as themillimetric waves
ECE Board Exam November 1998It frequency range of 401.000 MHz to 401.050 MHz has to be channelized at 12.5 kHz between channel, what is the center of its first channel from the lower limit?
ECE Board Exam April 1998Type of modulation used in TV broadcast visual transmitter.Vestigial sideband
ECE Board Exam November 1997In the designation of bandwidth and emission, what letter in the first symbol represent a double-sideband type of modulation?A
ECE board Exam March 1996The carrier swing necessary to provide 80% modulation in the FM broadcasting band is ____
ECE Board Exam April 2001One of the following refers to an output of a balanced modulator.DSB
ECE Board Exam March 1996In AM, the carrier carries _____ intelligence.no
ECE Board Exam March 1996Three audio waves with 100, 200, amd 300 volts amplitude respectively, simultaneously modulate a 450 volts carrier. What is the total percent of modulation of the AM wave?
ECE Board Exam March 1996Cross modulation on a receiver is eliminated at thedetector stage
ECE Board Exam March 1996If the percentage modulation of an AM amplifier is 88% and the modulating signal is 1 volt, the carrier has an amplitude of
ECE Board Exam November 1999One of the following is also considered major reason in adopting a modulation/demodulation processes in radio communication transmission instead of transmitting directly the intelligence signal.A mile length of transmission antenna is impractical.
ECE Board Exam April 1999Intelligence signal in radio modulation transmission technique is not calledHarmonics
ECE Board Exam November 1998In amplitude modulation technique the unmodulated carrier is referred to as having0% modulation
ECE Board Exam April 1998If a transmitter supplies 8 kW to the antenna when it is unmodulated, determine the total radiated power when modulated at 30%.
ECE Board Exam March 1996What is the difference between phase and frequency modulationLies in the different definitions of the modulation index.
ECE Board Exam April 1997What is the local oscillator frequency range in commercial AM broadcast if it is equal to 455 kHz?
ECE Board Exam November 1999Which of the following signal is suppressed by balanced modulator circuit?Carrier signal
ECE Board Exam November 1998A third symbol in radio emission which represents telephone transmission including sound broadcasting.E
ECE Board Exam April 1998How can receiver desensitizing be reduced?Decreased the receiver squelch gain
ECE Board Exam March 1996In an FM receiver, which circuit removes amplitude variations?Limiter
ECE Board Exam March 1996
After the IF stages have been aligned, the next stage to align in FM receiver islocal oscillator.
ECE Board Exam November 1999Refers to the emission on frequency(ies) immediately outside its necessary bandwidth, resulted from the modulation process except spurious emission.Out of band
ECE Board Exam April 1999The first symbol of an emission designation having an amplitude modulated main carrier represented by letter C is referred to asvestigial sideband
ECE Board Exam November 1998 Which of the following is referred to as a radio emission without sidebands. Carrier
ECE Board Exam March 2996What is the primary advantage of DSBSC in AM?No transmitter power is wasted in the carrier
ECE Board Exam November 1998 One of the following is not among the advantages of series modulation.Suppressed white noise
ECE Board Exam April 1999 What type of emission is produced when a frequency modulated transmitter is modulated by a facsimile signal?F3C
ECE Board Exam November 1998Type of emission produced by one of the early radio transmiotter trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier.Spark Emission
ECE Board Exam April 1999What is the modulation of index of an FM transmitter whose frequency deviation is 50 kHz, while its audio frequency is 10 kHz?
ECE Board Exam November 1998What is meant by the term deviation ratio?The ratio of the maximum carrier frequency deviation to the highest ECE Board Exam November 1998
One of the FM signal generator control which varies the phase of the modulating voltage applied to the oscillator of the sweep generator.Phase control
ECE Board Exam November 1998In the modulation technique, which of the following is referred to audible pitch?Harmonic
ECE Board Exam November 1998Assuming a UHF frequency range of 405.0125 MHz to 405.0875 MHz at 25 kHz channeling plan, how many channels can you produce?
ECE Board Exam November 1998A modulation which does not follow the sine wave pattern, it produces undesirable harmonics such as spurious emission.Over-modulated
ECE Board Exam April 1999What is the capture effect?The loudest signal received is the only demodulated signal.
NOISE…
Noise (C4 Past board: excel)
ECE Board Exam November 2000Generally referred to as the primary cause of atmospheric noise.Lightning
ECE Board Exam April 2000Absence of one of the following components in a parametric amplifier renders, this circuit a low-noise amplifier.Resistance
ECE Board Exam November 1998What is the major cause of atmospheric or static noise?Thunderstorm
ECE Board Exacta April 1998Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver?In the receiver front end
ECE Board Exam November 1997Extra-terrestrial noise is observable at frequencies from8 to 1.43 GHz.
ECE Board Exam April 1997________sets a limit on the maximum capacity of a channel with a given noise level,Shannon-Hartley theorem
ECE Board Exam November 1996Noise from random acoustic or electric noise that has equal per cycle, over a specified total frequency band.Thermal noise White noise Gaussian noise
Board Exam April 1998Referred to as the stage in the radio receiver that contributes most of the noise.Mixer
Board Exam November 1997NOise caused by the thermal agitation of electrons in resistanceThermal noiseJohnson's noiseWhite noise
ECE Board Exam April 1997Industrial noise frequency is between5 to 160 MHz . ECE Board Exam March 1996At what power level does a I kHz tone cause zero interference (144 weighted)?-90 dBm ECE Board Exam November 1997Background noise is the same as the following exceptimpulse noise. ECE Board Exam April 1997Reference noise temperature.290 Kelvin ECE board exam November 1996Noise reduction system used for film sound in movie.dolby
ECE Board Exam March 1996
A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver's noise temperature?
ECE Board Exam April 1997That is the reference frequency of CCITT psophometric noise measurement?800 Hz
ECE Board Exam November 1997atmospheric noise is less severe at frequencies above audio level.30 MHz
ECE Board Exam November 1997Two resistors, 20 kilo ohms and 50 kilo ohms are at ambient temperature. Calculate for bandwidth equal to 100 kHz, the thermal noise voltage for the two resistor connected in parallel.
ECE Board Exam March 1996The equivalent noise temperature of the amplifier is 25 K. What is the noise figure?
ECE Board Exam November 1997 nif stands for..noise improvement factor
ECE Board Exam April 1997Which does not affect noise in a channel?Quantizing level
ECE Board Exam March 1996The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is
ECE Board Exam March 1996 ..What does the noise weighting curve show?The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
ECE Board Exam November 1997The most common unit of noise measurement in white noise voltage testingNPR
ECE Board Exam April 1997The random and unpredictable electric signals form natural causes, both internal and external to the system is known as
Noise
ECE Board Exam March 1996The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the same bandwidth.Residual noise level
ECE Board Exam November 1997A figure of merit used to measure the performance of a radiation detector.Noise equivalent power
ECE Board Exam April 1997The most common unit of noise measurement in white noise testingNPRECE Board Exam March 1996In measuring noise in a voice channel at a -4 dB test point level, the meter reads -70dBm (F1A weighted), convert the reading into pWp.
ECE Board Exam April 1998Considered as the main source of an internal noiseThermal agitation
ECE Board Exam April 1997Unit of noise power of psophometer.pWp
NOTES…
GEAS 1
Employee's perception on the probability that he or she gets what he/she expectsExpectancy Theory
The type of leadership appropriate when manning professionalsfree rein leadership
"A satisified employee is motivated from within and a dissatisified employee is not motivated"Herzberg's Two-factor theory
The kind of authority usually given to budgets officers in the organizationfunctional authority
The type of organization for small firms
functional organization
The process that focuses on how subunits can use allocated resourcesintermediate planning
The type of reward that includes money, promotion..extrinsic reward
types of rewardsextrinsic or intrinsic
The type of power in the people of higher position towards those in the lower position in the organizational heirarchylegitimate power
Measure the ability to learnaptitude test
The type of control when the engineer manager collects data on a completed task, and evaluation,comments, and suggestions on how to improve the taskfeedback control
Temperature unchanged, The pressure of an ideal gas is inversely proportional to its volumeboyle's law
The rankine value that refers to the absolute temperature460 degrees Fahrenheit ( alam ko negative to.. please check sa notes )
The average kinetic energy of a gas is directly proportional to itsabsolute temperature
according to the modern view of the atomic modelelectron cloud..
the quantum number that refers to the spin of the electronspin quantum number
permeability is slightly greater than 1aluminum
Used in DNA making?zinc
Used to make galvanized ironzinc
most common metal mixed with copperzinc
the first law of thermodynamics is also calledlaw of conservation of energy
states that the amount of heat that is converted into heat is dependent on the temperature where it takes placesecond law of thermodynamics
the process in which a highly energetic particle transfers energy to an adjacent less energetic particleconduction
emission of electromagnetic waves or photonsradiation
a device that transfers heat between fluids without mixing the twoheat exchanger
Ideal Gas Constant8.314 kJ per kmol-K
Series of changes or processes in the system that repeatsCYCLE
At standard temperature and pressure, the volume of 1 mol isSAME FOR ALL PERFECT GASSES.
Reluctance of an object to change its state of rest or its uniform motionINERTIA
1 slug14.6 kg.
1 lb4.45 Newtons
The law of reaction - "For every force that acts on one body, there is a second force equal in magnitude but opposite in direction that acts upon another body."Third law of Motion
The law of acceleration - " Whenever a net resultant force acts on a body, it produces an acceleration in the direction of the resultant force that is directly proportional to the resultant foce and inversely propoportional to the mass of the body."Second law of Motion
The law of inertia - "There is no change in the motion of the body unless an unbalanced external force is acting upon it."First law of Motion
pHPositive Hydrogen ion
pH 1 to 6Acid
Mass of electrons in grams9.107 times 10 to the -28
Mass of protons in grams1.672 times 10 to the -24
Mass of neutron in grams1.675 times 10 to the -24
Charge of electron negative1.602 times 10 to the -19
charge of proton1.602 times 10 to the -19
Charge of neutron0
The mass of the neutron is approximately 1,839 times greater than electrons1839
The mass of the proton is approximately 1,836 times greater than electrons1836
Top 3 conductorSilver, Copper, Gold
least conductornichrome
atomsbuilding blocks of engineering materials
Aluminummost abundant metal in earth
Ductilityratio of ultimate shear to yielding stress
period thetime taken by a body in uniform motion to travel an orbit
760 torr equal to1 ATM
Charle's LawConstant Pressure, Variable Temperature and Volume
Twice amplitudetwice maximum velocity
R.A. 8792Philippine Electronic Commerce Act or E-Commerce Act
each orbital has 1 electron placed in it before pairing of electron in orbitals occursHunds' Rule
angular speed (momentum)Spin Quantum #
resistance(internal friction) of fluids to flowviscosity
S.I. unit of pressure Newton per square meterPascal
losses due to friction in oscillationdamped oscillator
cohesive attraction that causes liquid to minimize its surface areasurface tension
Maximum stress before permanent deformationelastic limit
also known as modulus of rigidityshear modulus
thermodynamic propertiesvolume, pressure, temperature
defined as mass per unit volume. Independent of size and shapedensity
another term for specific gravityweight density
ability of metal to be permanently deformedductility
elastic modulus applicable to liquidsbulk modulus
Combine two small elementsfussion
Larger element divided into 2 smaller elements…Fission
object subjected to equal and opposite forces on different lines of direction is said to be undershear stress
unit of mechanical shearjoule
conduction bandwhere free electrons move
gives off a yellow green appearanceChlorine
Gives off blue-black-violet colorIodine
young's modulus is also known asmodulus of elasticity
stress at which a material begins to plastically deformyield strength
irregularity within a crystal structureDislocation
most common defect of crystalLine defect
What is the S I unit of momentum kg. meter per sec.
Kg-m / s
What is the S I unit of impulse Newton - sec.N-s
total momentum of a closed system is constantConservation of linear momentum
number of cycles as a result of timeperiod
A common copper alloyZinc
a solution that is a liquid conductorelectrolyte
determines the acidity or basePH measurement
what is PH 7neutral
delegation of authorityassigning of different degrees of authority
Vander Waals bondingConnection between crystal atoms / forms eight pairs of electrons when bonded
Covalent bondingaggregate less when near each other than when separated from one another
metallic bondinginteraction of ionic lattice and electron gas
electrostaticbonding bonding between positive and negative charges
atomic numberelement identity
spin quantumdirection
Elementa pure substance that cannot be broken down by chemical means to a simpler substance.
Valence Electronsdetermines the ability of atoms to combine with other atoms.
Nitrogen GroupV - A
Electronics Engineer appearnce fee per hour500
Electronics engineer retainer's fee1500
maximum allowable exposure to radiation from an electronic equipment must not exceed to, 100 ms
keystone of professional conductintegrity
Requiring the services of a duly licenced ECE… planning, designing…Department Order No. 88
law provides for the regulation of radio station, communications in the Phils.R.A. 3846
policy to improve the provision of Local Exchange carrier serviceE.O 109
Foundation of Moral philosophyJustice, Honesty and Courtesy
Philippines is under what region in terms of frequency allocationRegion 3
Data network operated by enfranchised telecommunications carrier that is authorized to provide data.Public Switched Data Network
An ECE board member must be a citizen & resident of the Philippine for at least, BLANK, consecutive years prior to his appointmnt5 Years
Testing and quality control of electronics productManufacturing
If the engineer approves that a certain electronic product were according to engineering
standard..( something like this )Acceptance
Implementing rules and regulations ( IRR ) of R.A 9292August 31, 2007
Electronic Commerce Act of 2000R.A. 8792
VOIP service provider performance bond5 million
The certificate of Authority issued by NTC to A CATV maximum term.15 years
Maximum effective radiated power in Metro Manila and Metro Cebu for Channels 7 - 131000 Kw
Metro Manila Commercial load in radio stations15 minutes
Minimum carrier power output of a Standard AM Broadcast … direct supervision of an Electronics engineer is required1 Kw
Maximum power allocation for AM broadcast in Metro Manila50 kW
at what temperature does a magnetic material loses its ferromagnetic propertiesCurie Temperature
Specific Gravity also termed asRelative Density
Moment of Inertia is dependent onMass, Axis of rotation, Size and Shape
diatonic scale with added 5 half tonesChromatic Scale
binds the protons and neutrons together in the nucleus of an atomexchange force
depend on the number of harmonics present…Quality of Sound
Avogadros Number 6.022 x 10 to the ___ power23rd
controlled testing of the properties of a substance or system through carefully recorded measurements Experiment
father of scientific methodGalileo
number of S.I. base units7
Father of Modern ChemistryAntoine Lavoissier
means indivisibleAtomos
Pressure held constald, Volume of gas is inversely proportional to volumeCharles Law
Naming Chemical CompoundsChemical Nomenclature
Best Conductor of ElectricitySilver
Denser metal settles on less denseFloatation
the closeness of two sets of measured group of valuesPrecision
bending of a strip of metalElastisity of Flexion
twisting of springElasticity of Torsion
Acid and base balancedNeutralization
lacking of mass over something…Mass defect
where fission is controlledNuclear Reactor
operating at low temperatureCryogenics
what property of plastic changes with heat distortionMechanical
increasing in the small diameter tube with fluidCapillarity
Relating 2 different volume / densityRelative Humidity
Speech density… “volume”Absolute Humidity
Density of material with respect to density of airSpecific humidity
Same/Like materialsCohesion
Different/Unlike materialsAdhesion
Necessary nuclear reactor (uranium)Critical Size
RadioactivityCurie
Flow of fluid in pipe; “pressure”Bernoulli principle
“atomic mass”Physicists atomic weight
High production, something will limitLaw of diminishing return
Mix different quantities of some elementLaw of multiple proportion
Indistinguishable liquid and gas
Critical Point
Constant angular momentum, increasing kinetic energyKepler’s Law
Light actually passes throughReal image
Light seemed to pass throughVirtual image
Capital mobile dealerP 100,000
“Defect of lens”, “Rays near the edge”Spherical Aberration
“comet-shaped”coma
“Differences in vertical and horizontal distance”Astigmatism
Unit of electrostatic chargeStatvolt
SI unit of potential differencevolt
Electrostatic measuring device?Leaf electroscope
Class B FM500 ft.
Primary FM stations allowed of how many translators2
Acids formed from weak bases dissolved in H2OHydrolysis
Matter can be broken downDemocritus
Property of gas equals individual propertyGibb’s Theorem
NeutronChadwick
Summary observed factScientific Law
Partial volumeAzamat's Theorem
Liquid not used as solvent in a chromatographyWater
Not an ionization BondC6H12O6
1 molecule enters an orbit, spread, about atom spinHund’s rule of multiplicity
AM primetime6:00 AM – 8:00 PM
Change of temp w/o change of phaseSensible Heat
“oil or mining” / nauubos na resourcesDepletion Cost
Penetrate;moleculesDiffusion
Quantitative measurementStoichiometry
Shield for x-rayLead
(ratio of something to air to e)Absolute Index of Refraction
Incident angle is greater than critical angleTotal Reflection
Temperature, konting pressure na lang solid to liquid naCritical Temperature
Removal of EnergyWater to ice
Separation of liquid through because of difference in its boiling pointsDistillation
1 dyne on separation of 1 cm1 stat coloumb
Non performance that results in the injured party receiving something substantially less than or different from what the contract is intended.Material Breach
1 Joule10 raise to 7 ergs 10^7
ability to be mixed with otherMiscibility
Used as solute in stainless steel ( to prevent "kalawang" hehehe )Chromium
Used a slovent in stainless steelIron
Perfect absorberBlack Body
ratio of velocities before and after an impactcoefficient of restitution
Temperature where degree C = degree Fahrenheit- 40degrees
Used in Vehicle BaterriesSulfuric Acid
Medium… travels fast at zero degrees ( 0 deg C)Glass
Something about Bouyancy of material to waterArchimedes Theory
heat exceeds saturation at less pressureSuperheated
second most abundant element on earthoxygen
energy gap of GaAs1.43 V 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: GEAS, Notes
Wednesday, October 5, 2011
GEAS
GEAS Mechanical energy of pressure transferred into energy of heatAns. enthalpy
For a common microscope the image formed by the eyepiece isAns. inverted
Added to nucleus of an atom without changing its chemical propertiesAns. alpha particle
Ester of glycerol with unsaturated fatty acidsAns. oils
Energy of an electron is assumed to be zero whenAns. it is far away from the nucleus
Chief ore of zincAns. Sphalerite
Punitive damageAns. Exemplary damage
Functional depreciationAns. obsolescence
Maritime communication lawAns. R.A. 3396
Brightness of light sourceAns. luminous intensity
Heated metal(hot bodies)Ans. Edison effect
Producer gas is a mixture of nitrogenAns. carbon monoxide
1BTUAns. 1054 Joules
ParamagneticAns. Chromium
How an element is connected to otherAns. Structural formula
Arrangement of atoms in a moleculeAns. affects the reactivity of molecules
False statementAns. convex mirror can be used as main objective in a reflecting telescope
Average decay timeAns. mean life
Weightless environment, attach a ball to a spring and spin, the acceleration vector of the ball isAns. always point inward towards you
Change a sample of solid to liquidAns. heat of fusion
Failure to regain its original size and shapeAns. elastic lag
Reciprocal of bulk modulusAns. compressibility
Period driving forceAns. resonance
Willingness of an atom to receive electronsAns. electron affinity
Temperature below the saturation temperature corresponding to its pressureAns. subcooled liquid
Venturimeter measures ___ of waterAns. velocity
Temperature where Joule Thomson effect is zeroAns. inversion
Unit of moment of inertiaAns. kg-m2
Copper alloy used as collectors for electric generatorAns. Tin bronze
Solution of weak acid and its conjugate base, or weak base and its conjugate acidAns. buffer
System remains infinitesimally closed to an equilibrium at all timesAns. quasi-equilibrium
Hydrocarbon contain one or more double bondsAns. alkene
Process of making hydrocarbon gasAns. Bosch
Factor of safetyAns. yielding stress over working stress
Propagate same speed as lightAns. heat wave
Ratio of market price per share to earnings per shareAns. price-earnings ratio
Degrees F equals degrees CAns. -40
Unit of ionization radiationAns. Becquerel
Water is electrolyzedAns. hydrogen and oxygen atoms are separated from each other.
Black lightAns. UV radiation
RetentivityAns. permanent magnet
Mass of atomic particles
Ans. mass spectrograph
3G bondAns. 300M
RefrigerantAns. Dimethyl ether
Amount of energy to fracture a given volume of materialAns. Impact strength
Theory of light emitted in discrete amountAns. Quantum theory
Cast iron hard and wear resistanceAns. white iron
Heat engine can’t transfer heatAn. 2nd law of thermodynamics
Reflected sound waves returnAns. echo
Irregular succession of compression and rarefactionAns. unpitched sound
Luminance of clear skyAns. 3200
Blackbody radiation emitted at freezing platinumAns. candle
Result of atmospheric refractionAns. mirage
Absorbs radiant energy and re emits it in wavelengthsAns. fluorescence
Design to detect radiation emanating from radioactive sourceAns. Quartz-fiber electroscope
Monosodium Glutamate (MSG)Ans. vegetable protein
KwashiorkorAns. lack of protein
DownerAns. seconal
Decay of a neutron to a protonAns. beta particle
Known concentrationAns. standard solution
A pressure measuring device to register the pressure at all timesAns. mercury manometer
Work done is zero.Ans. isometric
Drink salt waterAns. cell shrink
SpeakerAns. 5 CU
DoctoralAns. 45 CU
Gas is produce by the action of sunlight on automobile exhaustAns. ozone
Middle management levelAns. intermediate planning
Process identifying and choosing alternative courses of action in a manner appropriate to the demands of the situationAns. decision-making
Documents that shows proof of legal ownership of a financial securityAns. Coupon
Color that bends the leastAns. red
Series of closets connected by slots or short conduit sleeves between floors or open shaft of the buildingAns. riser shaft
Upon dissociation in water, acid yields hydrogen ions while gases yields hydroxide ions
Ans. Arrhenius theory
Friendliest metalAns. Iron0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: GEAS, Notes
Tuesday, October 4, 2011
GENERAL ENGINEERING AND APPLIED SCIENCES
GENERAL ENGINEERING AND APPLIED SCIENCES
Carnot engine when reversed becomes Refrigerator
Highest average translational kinetic energy account to which state of matter Gas
Aluminum is the lightest among the following metals except Magnesium
Alpha particle test charge +2
Strength and machinability Normalizing
Middle C 256Hz
Radioactive source activity Becquerel
The frequency of Middle C 256Hz
Which of the following noble gases is most abundant on earth? Argon
Given mass 1=mass 2=132 lb, distance=1 meter, calculate gravitational force. 2.4 x 10^-7 N
Which of the following is the difference between ground state and excited state of an atom? Electron configuration
Helmholtz free energy is the internal energy of the system ____ Minus the product of entropy and temperature
The escape velocity on earth is 11,200 m/s. What is the escape velocity to the moon? 2,400
The material known as austenite is transformed into bainite when subjected to ___ process. Rapid cooling
Newly SROP provided that devices ___ output power Shall not exceed 25 watts
What is the value of resistivity of aluminum in ohm-m? 2.7 x 10^-8
As stated under D.O.88 for AM broadcasting station, operation sation must be under the supervision of registered ECE if the carrier power exceeds ___ 1kW
What is the unit charge of alpha particle? +2
Sound interference is required in order to attain the phenomenon known as Beats
Aside from platinum, gold, and silver, which is considered as a noble metal? Iridium
What is the velocity of a 100g ball on a 5cm string moving in horizontal circle that requires centripetal force of 1.0N? 2.2m/s
What is the coefficient unit of viscosity? Poise
What is the main characteristic of super__ whose major application are jet engines and gas turbines? Heat resistant
Which ferromagnetic is BCC crystal structure? Iron
What is the force of gravitational attraction between two 132-lb student who are standing 1m apart? 2.4 x 10^-7 N
Which of the following would be different in ground state and excited state upon atom? The electron configuration
Another aspect of pressure and human body is blood pressure. 20/20 vision is ideal…120/80, what is the unit? mmHg
What is the amount of time of activity may delayed without changing the succeeding activity? Slack
One Dalton is equivalent to how many MeV? 931
In alloy nickel is replaced by ___ to produce superinvar alloy. Cobalt
Chart compare planned schedule information to actual. Tracking Gantt Chart
PRC Modernization Act 8981
Type of brass with 85% copper Red brass
What is the ratio of working temperature to the temperature of melting point? Homologous temperature
Type of management that spend most of the time outside Management by wandering 1 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: GEAS, Notes
CHAPTER 18 COMMUNICATIONS
CHAPTER 18 COMMUNICATIONS
1. The circuit that recovers the modulating signal form 455 kHz intermediate frequency. Detector
2. Picks up all the radiated signals and feeds them into the RF amplifier. Antenna
3. Provides a dc level out of the detector that is proportional to the strength of the received signal
Automatic Gain Control (AGC)
4. It brings the high frequency audio signals back to the proper amplitude relationship with the lower frequencies De-emphasis Network
5. Removes any unwanted variations in the amplitude of the FM signal as it comes out of the IF amplifier and produces a constant amplitude FM output at the 10.7 MHz intermediate frequency Limiter
6. A feedback circuit consisting of a phase detector, a low pass filter, and a VCO PLL
7. The range of frequencies over which the PLL can acquire lock with an incoming signal Capture range
8. The angle that defines whether a light ray will be reflected or refracted as it strikes a surface. Critical Angle
9. A linear device that produces an output voltage proportional to the product of two input voltages Four-quadrant Multiplier
10. An optical characteristic of a material that determines the critical angle. Index of refraction
11. A device for down-converting frequencies in a receiver system Mixer
12. The RF amplifier, mixer, and local oscillator are tuned simultaneously so that the LO frequency is always 455 kHz above the incoming RF signal frequency. Gang tuning
13. A special case of the multiplier that is realized by simply applying the same voltage to both inputs by connecting the inputs together. Squaring circuit
14. Reverse modulation Demodulation
15. The process of varying a parameter of a carrier signal with an information signal. Modulation
16. Most VCOs employed in PLLs operate in the principle of ____________ using the varactor
diode as a voltage-variable capacitor. Variable reactance
17. The range of frequencies over which the PLL can maintain lock Lock range or tracking range
18. Independent of the bandwidth of the low-pass filter because when the PLL is in lock, the difference in frequency is zero or a very low instantaneous value the falls well within the bandwidth. Hold-in range
19. Uses light pulses to transmit information through fiber-optic cables. Fiber optics
20. Fiber optic cable in which the diameter of the core is fairly large relative to the diameter of the cladding. Multimode step index
21. Fiber optic cable in which the diameter core is very small relative to the diameter of the cladding. Single-mode step index
22. Fiber optic cable in which the diameter of the core is fairly large relative to the diameter of the cladding. Multimode graded index
23. A linear multiplier can be used as a _________ detector Phase
24. The output of a linear multiplier is the ________ of the inputs and a scale factor Product
25. The IF in a standard AM receiver is 455 kHz
26. A form of amplitude modulation in which the carrier is suppressed Balanced modulation
27. Another term for balanced modulation Suppresses-carrier modulation 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Electronics, Notes
CHAPTER 17 VOLTAGE REGULATORS
CHAPTER 17 VOLTAGE REGULATORS
1. The percentage change in the output voltage for a given change in the input voltage Line regulation
2. The percentage change in output voltage for a given change in load current Load regulation
3. Occurs when the internal power dissipation becomes excessive and the temperature of the device exceeds a certain value Thermal Overload
4. An electronic circuit that maintains an essentially constant output voltage with a changing input voltage or load current Regulator
5. Typical of three-terminal IC regulators that provide a fixed negative output voltage. 79XX
6. An example of a three-terminal positive regulator with an adjustable output voltage. LM317
7. Negative output counterpart of the LM317 LM337
8. A universal device that can be used with external components to provide step-up, step-down, and inverting operation 78S40
9. A voltage regulator in which the control element operate as a switch Switching regulator
10. Two basic types of linear regulators are Series and shunt
11. In linear series regulator, the control element is a transistor in _______ with the load Series
12. In linear shunt regulator, the control element is a transistor in _______ with the load. Parallel
13. A change in input voltage does not significantly affect the output voltage of a regulator. (true/false) True
14. Can be used as a current source when an application requires that a constant current be supplied to a variable load. Three-terminal regulator
15. Amplitude modulation is a ____________________process Multiplication
16. is one method used to overcome the bandwidth limitation of the telephone system so that digital data can be sent over the phone lines. FSK 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Regulators
CHAPTER 16 OSCILLATORS
CHAPTER 16 OSCILLATORS
1. A circuit that produces a periodic waveform on its output with only the dc supply voltage as an input Oscillator
2. The two major classifications for oscillators are feedback oscillators and _______________. Relaxation oscillators
3. Characterized by the condition wherein a portion of the output voltage of an amplifier is fed back to the input with no net phase shift resulting in a reinforcement of the output signal Positive signal
4. An amplifier gain of greater than ________ will cause the oscillator to limit both peaks of the waveform 100
5. The most widely used type of RC feedback oscillator for frequencies up to about 1 MHz Wien-bridge
6. Quarts is one type of crystalline substance found in nature that exhibits a property called ________ Piezolelectric effect
7. This type of LC feedback oscillator uses transformer coupling to feed back a portion of the signal voltage. It is sometimes called a “tickler” oscillator Armstrong Oscillator
8. Devices that produce more than one output function
Function generators
9. A relaxation oscillator whose frequency can be changed by a variable dc control voltage Voltage-controlled oscillator (VCO)
10. ___________ oscillators include the Colpitts, Clapp, Hartley, Armstrong, and crystal-controlled Sinusoidal LC
11. ___________ oscillators include the Wien-bridge, phase-shift, and twin-T Sinusoidal RC
12. This type of oscillator used an LC circuit in the feedback loop to provide the necessary phase shift and to act as a resonant filter that passes only the desired frequency of oscillation Colpitts Oscillator
13. It is a variation of the Colpitts but with an additional capacitor in series with the inductor in the resonant feedback circuit Clapp Oscillator
14. He invented the Hartley oscillator and the Hartley transform, a mathematical analysis method , which contributed to the foundations of information theory Ralph Vinton Lyon Hartley
15. Similar to Colpitts except that the feedback circuit consists of two series inductors and a parallel capacitor Hartley oscillator
16. The most stable and accurate type of feedback oscillator uses a piezoelectric _________ in the feedback loop to control frequency. Crystal
17. The lowest frequency at which a crystal is naturally resonant. Fundamental frequency
18. For higher frequencies, the crystal must be operated in this mode Overtone mode
19. A type of relaxation oscillator because its operation is based on the charging and discharging of a capacitor Square-Wave oscillator
20. A two-state device whose output can be at either a high voltage or a low voltage level Flip-flop
21. For initial start-up, the voltage gain around the feedback loop must be greater that
1 (one)
22. The feedback signal in an Armstrong oscillator is derived by ________ coupling Transformer
23. A type of RC feedback oscillator which used two T-type RC filters used in the feedback loop, one has a low-pass response and the other has high-pass response Twin-T oscillator
24. A loop is created in which the signal sustains itself and a continuous sinusoidal output is produces Oscillation
25. The phase shift around the feedback loop must be effectively ________ degrees to sustain the state of oscillation 0°
26. The voltage gain around the closed feedback loop must be equal to _________ to sustain state of oscillation. 1 (unity)
27. The product of the amplifier gain and the attenuation of the feedback circuit Voltage gain
28. He was involved in the development of oscillators and vacuum tube push-pull amplifiers at Western Electric in the early 1900 Edwin H. Colpitts
29. The frequency in a VCO can be varied with a _______ controlled voltage Dc 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Oscillators
CHAPTER 15 ACTIVE FILTERS
CHAPTER 15 ACTIVE FILTERS
1. The ___________ of a band-pass filter is the ratio of the center frequency to the bandwidth. Quality factor
2. An active filter category that rejects the frequencies within a certain bandwidth and passes frequencies outside the bandwidth Band-stop filter
3. A filter response characteristic that provides a very flat amplitude response in the passband and a roll-off rate of -20dB/decade/pole Butterworth characteristic
4. Each filter in a cascaded arrangement is called ___________. Stage or section
5. It is one of the most common configurations for two-pole filter. It is also known as a voltage-controlled voltage source filter. Sallen-Key
6. A filter required to get a third-order low-pass response. This is done by cascading a two-pole Sallen-key low-pass filter and a single-pole low-pass filter Three-pole filter
7. Each additional filter in a cascaded arrangement adds _______dB to the roll-off rate -20 dB
8. The rate of decrease in gain, below or above the critical frequencies of a filter. Roll-off
9. Technology that enables the tracking and/or identification of objects. Radio Frequency Identification (RFID)
10. Four categories of active filters Low-pass, high-pass, band-pass, and band-stop
11. Low-pass bandwidth is equal to Cutoff frequency
12. Filters with the Bessel characteristic are used for filtering ________ waveforms Pulse
13. Two common types of band-stop filters. Multiple-feedback and state-variable
14. Tiny, very thin microchips with memory and a coil antenna RFID tags
15. This type of tag does not require batteries. The tag is inactive until powered by the energy from the electromagnetic field of an RFID reader Passive RFID tag
16. This type of tag is powered by a battery and is capable of communicating up to 100ft. Or more from the RFID reader.
Active RFID tag
17. Another type of tag that is a paper labelled with printing with the RF circuitry and antenna embedded in it. Smart label
18. The property of selecting signals with certain selected frequencies while rejecting signals with other frequencies. Selectivity
19. A pole is simply a circuit with how many resistor or capacitor? 1
20. The damping factor affects the filter response by negative feedback action. True/false True
21. The more poles a filter has , the faster its roll-off rate is True
22. Another term for state-variable filter Universal active filter
23. Two methods of determining a filter’s response by measurement Discrete point measurement and swept frequency measurement
24. Produces a constant amplitude output signal whose frequency increases linearly between two preset limits. Swept frequency generator
25. How many poles does a Sallen-Key high pass filter have? 2
26. The center frequency of a state variable resistor is set by the _______ circuits in both integrators, RC
0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Filters, Notes
Wednesday, September 28, 2011
CHAPTER 14 SPECIAL PURPOSE OP-AMP CIRCUITS
CHAPTER 14 SPECIAL PURPOSE OP-AMP CIRCUITS
1. Provides dc isolation between input and output Isolation amplifier
2. Ratio of the output current to the input voltage Transconductance
3. Transconductance is __________ of an OTA Gain
4. A comparator with hysteresis where the input voltage is large enough to drive the device into its saturated states Schmitt trigger
5. The ______________ of a number is the power to which the base must be raised to get that number. Logarithm
6. An amplifier that produces an output that is proportional to the logarithm of the input. Log amplifier
7. Used in applications where it is necessary to have an output current that is controlled by an input voltage. Voltage-to-current converter
8. The circuit used to detect the peak of the input voltage and store that peak voltage on a capacitor. Peak detector
9. The exponent to which the base e must be raised in order to equal a given quantity. Natural logarithm
10. In an OTA, transconductance varies with _________. Bias current
11. Amplifiers that are often used in HF communication systems, including fiber optics, for processing wide dynamic range signals. Log and antilog amplifiers
12. The key characterisctic of an instrumentation amplifier CMRR
13. The voltage gain of instrumentation amplifier is set by a Resistor
14. The log amplifier may use the ___________ junction of a BJT in the feedback loop
Base-emitter
15. The main purpose of an instrumentation amplifier is to amplify _____ signals that are riding on _____ common-mode voltages. small, large
16. The ___________ of an OTA is the input voltage times the transconductance Output current
17. The operation of log and antilog amplifiers is based on the __________ characteristics of a pn junction Nonlinear (logarithmic)
18. A log amplifier has a pn junction in the feedback loop, and an antilog amplifier has a pn junction in __________ with the input Series
19. In a peak detector, an op-amp is used as a __________ to charge a capacitor through a diode to the peak value of the input voltage. Comparator
20. A basic instrumentation amplifier is formed by three op-amps and ________ resistors, including the gain setting resistor. Seven (7)
21. An oscillator that can be either amplitude or pulse modulated by the signal from the input amplifier High-frequency oscillator 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 13 BASIC OP-AMP CIRCUITS
CHAPTER 13 BASIC OP-AMP CIRCUITS
1. A common interfacing process often used when a linear analog system must provide inputs to a digital system. A/D conversion
2. Method of A/D conversion that uses parallel comparators to compare the linear input signal with various reference voltages developed by a voltage divider Flash
3. Produces an output that is proportional to the rate of change of the input voltage Differentiator
4. The difference between the UTP and the LTP Hysteresis voltage
5. Used to generate pulse waveform from the sine wave output of the audio generator. Voltage comparator
6. When the output is at the maximum positive voltage and the input exceeds UTP, the output switches to the _________ negative voltage Maximum
7. Uses a capacitor in the feedback path which is open to dc. This implies that the gain at dc is the open-loop gain of the op-amp. Practical integrator
8. Gives an op-amp noise immunity Hysteresis
9. Used to detect positive and negative voltages by connecting a fixed reference voltage source to the inverting input of a zero-level detector. Nonzero-Level detection
10. A good example of hysteresis Thermostat
11. A comparator with three trigger points Schmitt Trigger
12. The output of Schmitt trigger is Pulse waveform
13. In a comparator with output bounding, what type of diode is used in the feedback loop? Zener
14. Necessary components for the design of a bounded comparator Rectifier and zener diodes
15. Type of circuit that uses comparators Nonzero-level detector
16. Variations of the basic summing amplifier Averaging and scaling amplifier
17. Differentiation of a ramp input produces a step output with an amplitude proportional to the
_________ Slope
18. Another term for flash Simultaneous
19. Integration of a step input produces a ramp output with the slope proportional to the _________ Amplitude 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 12 THE OPERATIONAL AMPLIFIER
CHAPTER 12 THE OPERATIONAL AMPLIFIER
1. The measure of an amplifier’s ability to reject common-mode signals CMRR
2. It is the typical value of input offset voltage in the ideal case. 0 V
3. It is the dc current required by the inputs of the amplifier to properly operate the first stage. Input bias current
4. It is the resistance viewed from the output terminal of the op-amp Output impedance
5. The total resistance between the inverting and noninverting inputs Differential input impedance
6. Differential impedance is measured by determining the change in ___________ for a given change in differential input voltage. Bias current
7. Common temperature coefficient for the offset current 0.5nA/°C
8. Functions of negative feedback in an op-amp Stabilize gain and increase frequency response
9. The voltage gain of an op-amp with external feedback Closed-loop voltage gain
10. A special case of the noninverting amplifier where all of the output voltage is fed back to the inverting input by a straight connection Voltage-follower configuration
11. The value of the frequency at which the gain steadily decreases to a point where it is equal to unity Unity-gain frequency Or unity gain bandwidth
12. It is always equal to the frequency at which the op-amp’s open- loop gain is unity or 0 dB. Gain-bandwidth product
13. The relative angular displacement of a time-varying function relative to a reference. Phase shift
14. The three terminals of the basic op-amp not including power and ground Inverting input, noninverting input, and output
15. It has the highest input impedance and the lowest output impedance of the three amplifier configurations Voltage-follower
16. The _________ of an op-amp equals the upper critical frequency. Bandwidth
17. Two types of op-amp input operation. Differential mode and common-mode
18. A ____________ differentiator uses a capacitor in series with the inverting input. Ideal 19. An ideal op-amp has ___________ value for voltage gain, bandwidth, and input impedance. Infinite
20. What should be the output voltage of an op-amp when the differential input is zero Zero
21. The ideal op-amp has __________ output impedance Zero
22. The three basic op-amp configurations Inverting, noninverting, and voltage follower
23. The closed-loop voltage gain is _________ than the open-loop voltage gain. (more or less) Less
24. Does the gain of an op-amp decreases or increases as frequency increases above the critical frequency
Decreases
25. Devices such as the diode and the transistor which are separate devices that are individually packaged and interconnected in a circuit with other devices to form a complete, functional unit. Discrete components
26. Most op-amps operate with how many dc supply voltage? 2 (positive and negative)
27. Datasheets often refer to the open-loop voltage gain as the ______________ Large-signal voltage gain 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 11 THYRISTORS
CHAPTER 11 THYRISTORS
1. It is like the four-layer diode but with the added gate connection SCR
2. This is the maximum continuous anode current that the device can withstand in the conduction state under specifies conditions. Average forward current
3. What bilateral thyristor functions basically like two parallel SCRs turned in opposite directions with a common gate terminal? Triac
4. ____________ does not belong to the thyristor family because it does not have a four-layer type of construction. UJT
5. It can be used a trigger device for SCRs and triacs. UJT
6. It is a type of three-terminal thyristor that is triggered into conduction when the voltage at the anode exceeds the voltage at the gate. PUT
7. A region of forward bias in which the device has a very high forward resistance and is in the off state Forward-blocking region
8. A method for turning-off the SCR that basically requires momentarily forcing current through the SCR in the direction opposite to the forward conduction Forced commutation
9. The value of gate current necessary to switch the SCR from the forward-blocking region to the forward-conduction region under specified conditions. Gate Trigger Current
10. A four-layer semiconductor device that operates essentially as does the conventional SCR except that it can also be light-triggered. LASCR
11. Functions basically like two parallel 4- layer diodes turned in opposite directions. Diac
12. A diac with gate terminal Triac
13. A four-terminal thyristor that has two gate terminals that are used t trigger the device on and off Silicon Controlled Device (SCS)
14. A type of three-terminal thyristor that is triggered into conduction when the voltage at the anode exceeds the voltage at the gate. Programmable Unijunction Transistor (PUT)
15. The characteristic of a UJT that determines its turn-on point Standoff-ratio
16. The four-layer diode is also called Shockley diode
17. The region that corresponds to the on condition of the SCR where there is forward current from anode to cathode through the very low resistance of the SCR Forward_ conduction region
18. The SCR can only be turned on using its _________ terminal Gate
19. Acts as the trigger source in the LASCRs Light
20. A thyristor that conducts when the voltage across its terminals exceeds the breakover potential 4-layer diode
21. Basic methods of for turning off an SCR Anode current interruption and forced commutation 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Thyristors
CHAPTER 10 AMPLIFIER FREQUENCY RESPONSE
CHAPTER 10 AMPLIFIER FREQUENCY RESPONSE
1. The frequency at which the output power drops to one-half of its midrange value Corner frequency
2. At the critical frequencies the output voltage is 70.7% of its midrange value. What is the value of voltage gain in dB? -3 dB
3. What is the other term for lower critical frequency? All of the above
4. The condition where the gain is down 3 dB is logically called _________ of the amplifier response -3 dB point
5. The upper and lower dominant critical frequencies are sometimes called Half-power frequencies
6. A characteristic of an amplifier in which the product of the voltage gain and the bandwidth is always constant when the roll-off is -20 dB/ decade. Gain-bandwidth product
7. Critical frequencies are values of frequency at which the RC circuits reduce the voltage gain to ____________ of its midrange value. 70.7%
8. An octave of frequency change is a ________ -times change 2
9. Which of the following has no effect on the low-frequency response? Internal transistor capacitances
10. What is the gain that occurs for the range of frequencies between the lower and upper critical frequencies? Midrange gain 11. Which of the following is not a method in frequency response measurement?
Roll-off measurement
12. If the voltage gain is less than one, what is the value of the dB gain? Negative
13. A plot of dB voltage gain versus frequency on semilog graph paper Bode plot
14. The critical frequency at which the curve “breaks” into a -20dB/decade drop Lower break frequency
15. The change in gain or phase shift over a specified range of input signal frequencies Frequency response
16. A unit of logarithmic gain measurement and is commonly used to express amplifier response Decibel
17. The lower and upper critical frequencies of an amplifier can be determined using the _____________ method by applying a voltage step to the input of the amplifier and measuring the rise and fall times of the resulting output voltage Step-response method
18. The coupling an bypass capacitors of an amplifier affect the _________ frequency response: high or low Low
19. The internal transistor capacitances affect the _________ frequency response: high or low High
20. Two frequency response measurement Frequency/amplitude and step
21. The Miller input and output capacitances for a BJT inverting amplifier depends on Voltage gain
22. When dB is negative, it is usually called_______ Attenuation 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
Friday, September 23, 2011
CHAPTER 9 FET AMPLIFIERS AND SWITCHING CIRCUITS
CHAPTER 9 FET AMPLIFIERS AND SWITCHING CIRCUITS
1. An amplifier that primarily uses only MOSFETs. Class D
2. A process in which an input signal is converted to a series of pulses with widths that varies proportionally to the amplitude of the input signal. PWM
3. It removes the modulating frequency and harmonics and passes only the original signal to the output. Low-Pass Filter
4. The voltage gain of a common-drain amplifier is always Slightly less than 1
5. The load resistance connected to the drain of a common-source amplifier reduces ____________ Voltage gain
6. What is the relationship between the input resistance of a common-gate amplifier to its transconductance? They are inversely proportional
7. The efficiency of a class D amplifier approaches 100%
8. The input signal is applied to the gate and the output is taken from source Common-drain
9. A nonlinear amplifier in which the transistors are operated as switches Class D
10. A device that switches an analog signal on and off Analog switch
11. Consists of two or more analog switches that connect sample portions of their analog input signals to single output in a time sequence Analog multiplexer
12. Used in low-power digital switching circuits CMOS
13. Amplifier commonly used as frequency multiplier Class C
14. The least efficient amplifier Class A
15. An amplifier that is biased below cutoff Class c
16. A class of amplifier that operates in the linear region for only a small part of the input cycle Class C
17. In a class AB amplifier, if the VBE drops are not matched to the diode drops or if the diodes are not in thermal equilibrium with the transistors, this can result in Thermal runaway 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 8 FIELD –EFFECT TRANSISTORS
CHAPTER 8 FIELD –EFFECT TRANSISTORS
1. FETs are preferred device in low-voltage switching applications; while______ transistor is generally used in high-voltage switching applications. IGBT
2. What type of JFET operates with a reverse-biased pn junction to control current in the channel? JFET
3. An n-channel universal transfer characteristic curve is also known as Transconductance curve
4. The change in drain current for a given change in gate-to-source voltage with the drain-to-source voltage constant Forward transconductance
5. What is the most common type of JFET bias? Self-bias 6. It is a method for increasing the Q-point stability of a self-biased JFET by making the drain current essentially independent of gate-to-source voltage Current-source bias
7. What JFET bias uses a BJT as a constant-current source? Current-source bias
8. For increased Q-point stability, the value of RS in the self-bias circuit is increased and connected to a negative supply voltage. This sometimes called Dual-supply bias
9. VGS varies quite a bit for JFET self-bias and voltage-divider bias but ID is much more stable with Voltage-divider bias
10. ____________ is sometimes called depletion/enhancement MOSFET. D-MOSFET
11. LDMOSFET has a lateral channel structure and is a type of Enhancement MOSFET
12. It is an example of the conventional E-MOSFET designed to achieve higher power capability
VMOSFET
13. Following are the three ways to bias a MOSFET except Current-source bias
14. The insulated-gate bipolar transistor combines which two transistors that make it useful in high-voltage and high-current switching applications? BJT and MOSFET
15. What are the three terminals of IGBT? Gate, collector, emitter
16. In terms of switching speed, __________ switch fastest and _____________ switch slowest. MOSFETs, BJTs
17. In a MOSFET, the process of removing or depleting the channel of charge carriers and thus decreasing the channel conductivity Depletion
18. The ratio of change in drain current to a change in gate-to source voltage in a FET Transconductance
19. A FET is called a ______________ because of the relationship of the drain current to the square of a term containing gate-to-source voltage Square-law device 20. Combines features from both the MOSFET and the BJT that make it useful in high-voltage and high-current switching applications. IGBT
21. Has a lateral channel structure and is a type of enhancement MOSFET designed for power
applications. LDMOSFET 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Transistor
CHAPTER 7 POWER AMPLIFIERS
CHAPTER 7 POWER AMPLIFIERS
1. It is the product of Q-point current and voltage of a transistor with no signal input Power dissipation
2. The ____________ of an amplifier is the ratio of the output signal power supplied to a load to the total power from the dc supply. Efficiency
3. Which amplifier operates in the linear region for 180 deg. Of the input cycle when biased in cutoff and is in cutoff for 180 deg? Class B
4. These amplifiers are biased to conduct for slightly more than 180 deg. Class AB
5. An amplifier that is generally used in Radio Frequency applications Class C
6. Implemented with a laser diode Current mirror
7. An amplifier that is biased below cutoff and is normally operated with resonant circuit load Class C
8. The four classes of power amplifiers are classified based on the percentage of the ____________which the amplifier operates in its ________region Input cycle, linear
9. It is the ratio of the output power to the input power Power gain
10. Product of the rms load current and the rms load voltage Output power
11. A type of class B amplifier with two transistors in which one transistor conducts for one half-cycle and the other conducts for the other half-cycle
Push-pull
12. Amplifiers that are generally used in Radio Frequency Applications. Class C amplifiers
13. Another term for complementary Darlington Sziklai pair
14. An advantage of push-pull class B and class AB amplifiers over class A Efficiency
15. The Q-point is at _________ at class B operation Cutoff
16. Operates in the linear region where the output signal is an amplified replica of the input signal Class A
17. Amplifiers that have the objective of delivering power to a load Power amplifers
18. When the Q-point is at the center of the ac load line, a maximum class ________ signal can be obtained. A
19. The maximum efficiency of capacitively coupled class A amplifier cannot be higher than 25%
20. The low efficiency of class A amplifiers limits their usefulness to small power applications that require usually less than ________. 1 W 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes
CHAPTER 6 BJT AMPLIFIERS
CHAPTER 6 BJT AMPLIFIERS
1. Amplifiers designed to handle small __________ signals are referred to as small-signal amplifiers. ac only
2. Which of the r parameters is the most important? r’e
3. Determine the ac emitter resistance that is operating with a dc emitter current of 5mA. 5.0 Ω
4. If βac=hfe, αac=? hfb
5. Which of the three amplifier configurations exhibit high voltage gain and high current gain? Common-emitter
6. An amplifier configuration which has a voltage gain of approximately 1, a high input resistance and current gain, Common-collector
7. An amplifier configuration which provides high voltage gain with a maximum current gain of 1. Common-base
8. Which of the amplifier configurations is the most appropriate for certain applications where sources tend to have low-resistance outputs? Common-base
9. In a common-emitter amplifier, any change in input signal voltage results in Opposite change in collector signal voltage
10. The ac voltage gain is the ratio of ac output voltage at the collector to ac input voltage at the base
11. the reduction in signal voltage as it passes through a circuit attenuation
12. the overall voltage gain of the common-emitter amplifier is the product of the voltage gain from base to collector and reciprocal of the attenuation
13. Without the bypass capacitor, the CE amplifier’s emitter is no longer at ac ground. How does this affect the amplifier? It decreases the ac voltage gain
14. The measure of how well an amplifier maintains its design values over changes in temperature, Stability
15. Swamping is a method used to minimize the effect of the ____________without reducing the voltage gain to its minimum value. ac emitter resistance
16. ___________ contains two transistors. The collectors of two transistors are connected and the emitter of the first drives the base of the second. Darlington pair
17. _____________ consists of two types of transistors, npn and a pnp. Complementary Darlington
18. An amplifier configuration in which the input signal is capacitively coupled to the emitter and the output is capacitively coupled from the collector, Common-base
19. Which of the amplifier configurations is/are useful at high frequencies when impedance matching is required? Common-base
20. The power gain of a common-base amplifier is approximately equal to Voltage gain
21. BJT amplifier that produces output that are a function of the difference between two input voltages, Differential amplifier
22. Ideally, a diff-amp provides a very high gain for single-ended or differential signals and _____________ gain for common-mode signals. 0
23. Input signals are out of phase Differential amplifier 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Amplifiers, Electronics, Notes CHAPTER 5 TRANSISTOR BIAS CIRCUITS
1. What biasing method is common in switching circuits? Base bias 2. A Base bias in linear region shows that it is Directly dependent on dc beta
3. In an emitter-feedback bias, if the collector current increases, the emitter voltage Increases
4. What happens to the base voltage in no. 10? Increases
5. In an emitter-feedback, the increase in base voltage _________ the base current. Reduces 6. For collector-feedback bias, what provides the bias for the base-emitter junction? Collector voltage 7. As temperature goes up in a collector-feedback circuit, βDC and VBE goes _______ and __________, respectively. Up and down
8. Collector-feedback bias provides good stability using negative feedback from Collector to base
9. Innovations in technology would allow a doubling of the number of transistors in a given space every year and that the speed of those transistors would increase. This prediction is widely known as Moore’s law
10. If an amplifier is not biased with correct dc voltages on the input and output, it can go ___________ when an input signal is applied. Saturation or cutoff
11. Given a voltage-divider biased BJT, determine IC given VCC, R1, R2, RC, and RE which are 10V, 10kohms, 4.7kohms, 1kohm, and 470ohms respectively. Use βDC= 100. 5.31mA
12. What is the value of VCE in no.20? 2.19 V
13. If an emitter resistor is added to a base bias circuit, what is the value of the emitter current given VCC, RE, RC, and RB as 10V, 1kΩ, 470Ω, and 180kΩ, respectively. Use βDC=100. 3.32mA
14. Calculate for VCE in no. 22 5.12 V
15. If the dc beta in the preceding drops half of its original value, find the percent change in IC. 39.16%
16. What is the percent change in VCE? 27.17%
17. The region along the load line including all points between saturation and cutoff Linear region
18. A voltage divider for which loading effects can be neglected Stiff voltage divider
19. The base bias circuit arrangement has poor stability because its Q-point varies widely with Dc beta
20. The purpose of biasing a circuit is to establish a proper stable ________. Q-point
21. The process of returning a portion of a circuit’s output back to the input in such a way as to oppose or aid a change in the output Feedback 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Transistor
Saturday, September 10, 2011
CHAPTER 4 BIPOLAR JUNCTION TRANSISTORS
CHAPTER 4BIPOLAR JUNCTION TRANSISTORS
1. Which is the least of the three transistor currents?Base
2. The ratio of the dc collector current to the dc base current of the transistor is,dc beta/dc current gain
3. the ratio of the dc collector current to the dc emitter currentdc alpha
4. Determine the base current given dc beta=100 , dc alpha=0.85, and IC= 3.70mA0.037mA
5. Nonconducting state of a transistorCutoff
6. State of a BJT in which the collector current has reached maximum and is dependent of the
base current Saturation
7. Neither the base-emitter nor the base-collector junctions are forward-biasedcutoff
8. dc beta varies withcollector current and temperature
9. hFE varies with which transistor current/s?Collector only
10. Converts light energy to electrical signalPhototransistor
11. Devices used to electrically isolate circuitsOptocouplers
12. A key parameter in optocouplers is the CTR. CTR stands forCurrent transfer ratio
13. Indication of how efficiently a signal is coupled from input to outputCTR
14. RF transistors are designed to operate atEHF
15. What transistor category/ies uses plastic or metal packages?General-purpose transistors
16. To operate as an amplifier, BE junction must be forward-biased and the BC junction must be reverse-biased. This is calledForward-reverse bias
17. In a phototransistor, what transistor current/s is produced and controlled by light?Base
18. Two basic package typesThrough-hole and surface mount
19. The process of increasing the power, voltage, or current by electronic means.Amplification 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Transistor
CHAPTER 3 SPECIAL- PURPOSE DIODES
CHAPTER 3SPECIAL- PURPOSE DIODES
1. Diodes that were designed to operate in reverse breakdown Zener diode
2. A device that operates in reverse bias photodiode
3. A zener diode operating in breakdown acts as a Voltage regulator 4. A positive temperature means that the zener voltage Increases with an increase in temperature on decreases with decrease in temperature.
5. A diode that always operates in reverse-bias and is doped to maximize the inherent capacitance of the depletion region is Laser
6. When the light-emitting diode (LED) is forward-biased, __________pass the pn junction and recombine with____________ in the _________material. Electrons, holes, p-type
7. The first visible red LEDs were produced using GaAsp
8. The normalized output of the visible red, yellow, green and blue LED peaks at __________________ (nm) respectively. 660,590,540, and 460
9. Organic LEDs and LEDs produce light through the process of __________ and ___________ respectively. Electrophophorescence and electroluminescence
10. An increase in the amount of light intensity produces an increase in Reverse current
11. A diode that can be used as a variable-resistance device controlled by light intensity. Photodiode
12. A diode that operates only with majority carriers Schottky diode
13. A diode that takes advantage of the variable forward resistance characteristic. PIN diode
14. No reverse leakage current
Schottky diode
15. Diode used in VHF and fast switching applications Step- Recovery diode
16. When a PIN diode is forward-biased, it acts like a Current-controlled variable resistance
17. If a tunnel diode is placed in series with the tank circuit and biased at the center of the negative-resistance portion of its characteristic curve, a _________ will result in the output. Constant sinusoidal voltage
18. The tunnel diode is only used at VHF
19. In a varactor diode, what happens to the capacitance if the reverse-bias voltage decreases a. Increases
20. The varactor capacitance ratio is also known as a. Tuning ratio 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Diode, Electronics, Notes
CHAPTER 2 DIODE APPLICATIONS
CHAPTER 2DIODE APPLICATIONS
1. An open primary or secondary winding of a power supply transformer results in 0 V
2. The output frequency of a half-wave rectifier is _________to/of the input frequency Equal
3. What is the average value of the half-wave rectified voltage given 25 V as its peak amplitude? 7.95 V
4. The PIV rating of the bridge diodes is __________to/than that required for the center-tapped configuration. Less 5. Diode circuits used to clip off portions of signal voltages above or below certain levels, Clippers
6. The output frequency of a full-wave rectifier is ________ the input frequency Twice
7. A transformer is generally specified based on _____________rather than the turns ratio, Secondary voltage 8. The period of a full-wave rectified voltage is ____________ that of a half-wave rectified voltage Half
9. The indication of the effectiveness of the filter is called Ripple factor
10. Eliminates the fluctuations in the rectified voltage and produces a relatively smooth dc voltage Filter
11. Circuit that maintains a constant dc voltage for variations in the input line voltage or in the load Regulator
12. A type of full-wave rectifier that uses two diodes connected to the secondary of a center-tapped transformer Center-tapped rectifier
13. Use clamping action to increase peak rectified voltages without the necessity of increasing the transformer’s voltage rating Voltage multipliers
14. Maximum voltage appearing across the diode in reverse bias PIV
15. Caused by the charging and discharging of the filter capacitor Ripple voltage
16. A systematic process of isolating, identifying, and correcting a fault in a circuit or system Troubleshooting
17. Allows unidirectional current through the load during the entire 360° of the input cycle Full-wave rectifier
18. Allows current through the load only during one-half of the cycle. Half-wave rectifier
19. Generally used because of the surge current that initially occur s when power is first turned on Slow-blow type fuse
20. A figure of merit used to specify the performance of a voltage regulator regulation
OSCILLATORS…
CHAPTER 16 OSCILLATORS
CHAPTER 16 OSCILLATORS
1. A circuit that produces a periodic waveform on its output with only the dc supply voltage as an input Oscillator
2. The two major classifications for oscillators are feedback oscillators and _______________. Relaxation oscillators
3. Characterized by the condition wherein a portion of the output voltage of an amplifier is fed back to the input with no net phase shift resulting in a reinforcement of the output signal Positive signal
4. An amplifier gain of greater than ________ will cause the oscillator to limit both peaks of the waveform 100
5. The most widely used type of RC feedback oscillator for frequencies up to about 1 MHz Wien-bridge
6. Quarts is one type of crystalline substance found in nature that exhibits a property called ________ Piezolelectric effect
7. This type of LC feedback oscillator uses transformer coupling to feed back a portion of the signal voltage. It is sometimes called a “tickler” oscillator Armstrong Oscillator
8. Devices that produce more than one output function Function generators
9. A relaxation oscillator whose frequency can be changed by a variable dc control voltage Voltage-controlled oscillator (VCO)
10. ___________ oscillators include the Colpitts, Clapp, Hartley, Armstrong, and crystal-
controlled Sinusoidal LC
11. ___________ oscillators include the Wien-bridge, phase-shift, and twin-T Sinusoidal RC
12. This type of oscillator used an LC circuit in the feedback loop to provide the necessary phase shift and to act as a resonant filter that passes only the desired frequency of oscillation Colpitts Oscillator
13. It is a variation of the Colpitts but with an additional capacitor in series with the inductor in the resonant feedback circuit Clapp Oscillator
14. He invented the Hartley oscillator and the Hartley transform, a mathematical analysis method , which contributed to the foundations of information theory Ralph Vinton Lyon Hartley
15. Similar to Colpitts except that the feedback circuit consists of two series inductors and a parallel capacitor Hartley oscillator
16. The most stable and accurate type of feedback oscillator uses a piezoelectric _________ in the feedback loop to control frequency. Crystal
17. The lowest frequency at which a crystal is naturally resonant. Fundamental frequency
18. For higher frequencies, the crystal must be operated in this mode Overtone mode
19. A type of relaxation oscillator because its operation is based on the charging and discharging of a capacitor Square-Wave oscillator
20. A two-state device whose output can be at either a high voltage or a low voltage level Flip-flop
21. For initial start-up, the voltage gain around the feedback loop must be greater that 1 (one)
22. The feedback signal in an Armstrong oscillator is derived by ________ coupling Transformer
23. A type of RC feedback oscillator which used two T-type RC filters used in the feedback
loop, one has a low-pass response and the other has high-pass response Twin-T oscillator
24. A loop is created in which the signal sustains itself and a continuous sinusoidal output is produces Oscillation
25. The phase shift around the feedback loop must be effectively ________ degrees to sustain the state of oscillation 0°
26. The voltage gain around the closed feedback loop must be equal to _________ to sustain state of oscillation. 1 (unity)
27. The product of the amplifier gain and the attenuation of the feedback circuit Voltage gain
28. He was involved in the development of oscillators and vacuum tube push-pull amplifiers at Western Electric in the early 1900 Edwin H. Colpitts
29. The frequency in a VCO can be varied with a _______ controlled voltage Dc
PAST BOARDS…
Fiber Optics (Chapter 11: Past Board Excel)
ECE Board Exam April 2001Which of the following refers to the relative refractive index difference of single mode fibers?0.1 - 0.3 %
ECE Board Exam November 2000A parameter of light beam that do not change the quality when it enters one medium from another.Frequency
ECE Board Exam April 2000Which of the following limits the top speed of transmitting information in fiber optic communication?Detector speed
ECE Board Exam November 1999Type of multi-channel signal transmission in the optic fiber communication that uses twisted pair coupler to transmit two signals of different wavelengths.Frequency-division multiplexing
ECE Board Exam April 1999Best applies to an optical fiber core.A higher refractive index than the cladding
ECE Board Exam November 1998How many times bigger does the bandwidth of a fiber optic multimode have over cable?100 times bigger
ECE Board Exam April 1998What law does a light travelling in an optical fiber follow?Snell's
ECE Board Exam November 1997Band of light waves, that are too short to be seen by human eye.Ultraviolet
ECE Board Exam April 1997Insertion loss of connector-type splices for a single-mode fiber cable.0.38dB
ECE Board Exam November 1996An object father from a converging lens than its focal point always has an ________ image.inverted
ECE Board Exam March 1996The dielectric material of an optical fiber surrounding the core.Cladding
ECE Board Exam April 2001An optical time domain reflectometer used in fiber optic communication is not intended to determine one of the following:Kind of multiplexing
--------------------- An optical time domain reflectometer used in fiber optic communication-------Refractive indexLoss per kilometerLength of fiber
ECE Board Exam November 2000In wire communications system using fiber optic, the packing fraction is related to one of the following statements when referred to fiber optic bundle.
Ratio of the total cross-sectional area to the total cross-sectional area of the fiber bundle
ECE Board Exam April 2000Why are fiber optic cables considered less expensive compared to coaxial cables in communication system?Use of less repeaters
ECE Board Exam November 1999An optic fiber regenerator which is used in communication is consisting of a ________ to clean up and amplify digital data moving in one direction and a similar system for the opposite direction.transmitter and receiver
ECE Board Exam April 1999How do you account the effect of light intensity on the refractive index of a fiber optic?Increases
ECE Board Exam November 1998One of the following referred to as a major component of an optical time domain reflectometer.Pulse generator laser
ECE Board Exam April 1998__________ generates light beam at a specific visible frequency.Laser
ECE Board Exam November 1997The most common device used as a light detector in fiber optic communication system.APDs
ECE Board Exam April 1997A non-coherent light source for optical communications system.LED
ECE Board Exam November 1996The loss in signal power as light travels down a fiber isattenuation
ECE Board Exam March 1996It is made from semiconductor material such as aluminum-gallium-arsenide or gallium-arsenide-phosphide.Light emitting diode
ECE Board Exam April 2001How much bigger does the bandwidth of a single mode fiber optic have over the multimode fiber?20 times bigger
ECE Board Exam November 2000Which of the following refers to the bandwidth of optical fiber?1 MHz - 500 MHz
ECE Board Exam April 2000Refers to a characteristic of a multimode fiber optic.Cladding thickness is greater than the radius of the core and the diameter of the core must be much greater than the wavelength of the light to be carried.
ECE Board Exam November 1999What do you call the loss in signal power as the light travels the fiber optic?Attenuation
ECE Board Exam April 1999 One of the characteristics of a fiber optic used in order to carry light in several modes of propagation or to become a multimode fiber.Diameter of the core must be very muuch greater than the wavelength of the light to be carried.
ECE Board Exam November 1998What kind of effect is referred to a varying light producing a varying voltage output of a detector? Photovoltaic effect
ECE Board Exam April 1998Quantity that do not change when a beam of lifgt enters one medium to anotherFrequency
ECE Board Exam April 1997Type of fiber that has the highest modal dispersion.Step-index multimode
ECE Board Exam November 1997Calculate the energy of the photon of infrared light intensity at 1.55 um.
ECE Board Exam November 1996The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted is known as __________.
mode
ECE Board Exam March 1996An absorption loss caused by valence electrons in the siica material from which fibers are manufactured.Ultraviolet absorption
ECE Board Exam April 2001Which of the following is not a major component of an optical time domain reflectometer used in fiber optic communication?vertical and horizontal plates
-------------------- major component of an optical time domain reflectometer used in fiber optic communication---------------------LaserBeam splitterPulse generator
ECE Board Exam November 2000Which of the following is a part of an optical time domain reflectometer?Beam splitter
ECE Board Exam April 2000This refers to a certain material which is most sensitive to light.Photoresist
ECE Board Exam November 1999Referred to as a light source of fiber optic which supplies level of 5to 7 milliwats and having a narrow spectrum of emission.Injection laser diode
ECE Board Exam April 1999Most likely, how many times would a fiber optic break in a span of thirty years?2 - 3 times
ECE Board Exam November 1998An advantage of optic fiber rejecting an induced noise signal from magnetic field or solar storm fluxImmunity to noise
ECE Board Exam April 1998Which of the following colors of light rays has the shortest wavelength?Violet
ECE Board Exam April 1997
Fiber optic cable operates near ________ frequencies.800 THz
ECE Board Exam November 1997If a fiber optic system has a rise time of 38.55 ns, the source rise time is 12 ns and the detector rise time is 12 ns, what is the cable rise time?
ECE. Board Exam November 1996Proposed the used of a clad glass fiber as a dielectric waveguideBockham and Kao
ECE Board Exam November 2000ln electronic communications where fiber optic material is used, a reflectedwave is a possibility. what happen to the polarization of this reflected wavewhen compared to its original form?Shifts to 180 degrees
ECE Board Exam April 2000The effect of multimode propagation caused the rays leaving the fiber tointerfere constructively and destructively as they leave the end of the fiberthis effect is called _________.modal delay spreading
ECE Board Exam November 1999 What is the wavelength for deep violet light?500 nmeter
ECE Board Exam April 1999A device in the fiber optic that is used to attenuate the reflected signal from the polished end of the fiber which has a possibility of developing into a noise.Isolator
ECE Board Exam November 1998One of the advantages of the fiber optic which is referred to the volume of capacity of signals it can carryBandwidth
ECE Board Exam April 1998Circuit used to amplify the optical signal in fiber optics communications links.Optical repeater
ECE Board Exam November 1997A device that reduces the intensity of light in fiber optics communication systems
Optical attenuator
ECE Board Exam April 1997Lifetime of ILDs50.000 h
ECE Board Exam November 1996What is the stage of the sand becoming a silicon?Molten
ECE Board Exam November 2000One of the major limitations of a plastic fiberoptic used in communicationDue to its high losses
ECE Board Exam April 2000One of following is considered the largest source of signal power loss in theuse of fiber optic as communications medium such as due to misalignment.ConnectionECE Board Exam NOvember 1999One of the following is related to the application of solid material as a medium where light travels.medium where Ilght travels. apphcatlon of 5DHd mater-ja}; as 3Fiber optics
ECE Board Exam April 1999Which of the following is not considered as one of the causes for the loss of signal power as light travels through a fiber optic?Inter-modulation----------------causes for the loss of signal power as light travels through a fiber optic-----------------ScatteringFiber bendingAbsorption
ECE Board Exam November 1997The core of the optical fiber has _______a higher index of refraction than the cladding
ECE Board Exam November 1997Loss due to the diffraction of light when it strikes on the irregularities formedduring the manufacturing process of the fiber optics.Rayleigh scattering loss
ECE Board Exam November 1996If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time?
ECE Board Exam November 2000A phenomenon which causes the speed of light rays propagation in the fibermaterial changes, as it passes through different medium in the fiberRefraction
ECE Board Exam April 2000At what intenial does a fiber optic needs a repeater in communicationssystem?30 to 300 miles
ECE Board Eanm November 1999Referfeq to as a limit in reducing further the loss of signal passing through afiber optic caused by scattering.Rayleigh effect
ECE Board Exam April 1999These are band of light wavelengths, that are too short to be seen by the human eye.Ultraviolet
ECE Board Exam November 1998A quarter wavelength device made of crystalline calcite that changes polarization in the optic fiber communicationRetarder
ECE Board Exam April 1999At what power levels does fiber optic have when used in electronic communications?Range of micro to milliwatts
ECE Board Exam November 1998One of the following is among the types of fiber optics used in electronics communication.Semi-graded multimode
ECE Board Exam November 1998How do you reduce the loss that is produced when light strikes a flat polished end of a fiber optic?By application of antireflection coating ECE Board Exam November 1998What is the device use in used in fiber optic communication which consist of a receiver transmitter use tc clean up and amplify digital data moving in one direction and another in
opposite direction? Optic regenerator
ECE Board Exam November 2000An advantage of fiber optic over co-axial cable as a result of coupling signalsfrom one to the other due to changing magnetic field in one or both.Crosstalk
ECE Board Exam April 2001What is the index of refraction of a certain substance if light travels throughthe substance at 100 meters at a time is to 140 meters to air'?
0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Fiber Optics, Past Board
Saturday, June 16, 2012
Satellite Communications (Chapter 10: Past Board Exce)
ECE Board Exam April 2001What balance the gravitational pull of the earth to allow the satellite to stay on its orbit?Centripetal force
ECE Board Exam November 2000Satellite that rotates around the earth in a low-altitude elliptical or circular pattern.Nonsynchronous satellite
ECE Board Exam April 1999In a transoceanic satellite conversation, how much is the typical delay before a reply is heard?600 ms
ECE Board Exam November 1999What are the repeaters inside communications satellite known for?Transponders
ECE Board Exam April 2000Under a circular satellite orbiy, how high is a certain satellite located above the surface of the
earth if the total satellite height is 9869 miles?
ECE Board Exam November 1998 Is a kind of satellite which has a period of revolution equivalent to the period if rotation of the earth about its axis. Geosynchronous satellite
ECE Board Exam April 1998A radio land station in the land mobile service.Base station
ECE Board Exam November 1997The use of telecommunication for automatic indicating or recording measurement at the distance from the measuring instrument.Telemetry
ECE Board Exam April 1997_______________ is the horizontal pointing angle of an antenna.Azimuth
ECE Board Exam November 1996How many satellite orbital slots are requested by the Philippine government from ITU?6
ECE Board Exam MArch 1996The point on satellite orbit, closest to the earth isperigee
ECE Board Exam April 2001A mobile service between base stations and land mobile stations or between land mobile stations.Mobile service
ECE Board Exam November 2000Which of the following refers to the basic component of a communication satellite receiver?Transponder
ECE Board Exam April 2000Determine from the following the basic technique used to stabilize a satellite.Spin
ECE Board Exam November 1999A space distance iin satellite communication from the earth, to or greater than 2,000,000 kilometers is referred to as ___________.deep space
ECE Board Exam April 1999How many satellites does the GPS system consist?24 satellites
ECE Board Exam November 1999Which point on the satellite orbit is closest to the earth?perigee
ECE Board Exam November 1998Which of the following is refers to the smallest beam of a satellite antenna's radiation pattern?spot beam
ECE Board Exam April 1998A major and basic advantage for the use of klystron.Hiigh power
ECE Board Exam November 1997Station in the mobile service not intended to be used while in motion.Land station
ECE Board Exam April 1997__________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency.LNB
ECE Board Exam November 1996Collects very weak signals from a broadcast satellite.Satellite dish
ECE Board Exam March 1996It is a spacecraft replaced in orbit around the earth carrying onboard microwave receiving and transmitting equipmentsCommunications satellite
ECE Board Exam April 2001A what apogee in an elliptical orbit must a geosynchronous satellite be initially stationed before it is finally fired into its final geostationary orbit?22,300 miles
ECE Board Exam November 2000
Satellite orbit around the earth are either:they are either circular or elliptical
ECE Board Exam April 2000Satellite system or part of a satellite system, consisting of only one satellite and the cooperating stations.Satellite network
ECE Board Exam November 1999A resultant effect in launching a satellite from the earth caused by both forward motion away from the earth that provides inertia tending the satellite to travel in straight line upwards and the gravitational pull towards the earth is referred to as ___________.centripetal acceleration
ECE Board Exam November 1998Which of the following refers to the first active satellite?Sputnik 1
ECE Board Exam April 1998A band where most military satellite often operate.X
ECE Board Exam November1997Known to be the first satellite capable to receive and transmit simultaneously.Telstar I
ECE Board Exam April 1997What kind of battery panels are used in some advanced satellites?Gallium arsenide solar panels
ECE Board Exam November 1996Satellite signal transmitted from a satellite transponder to earth's station.Downlink
ECE Board Exam November 1999In satellite communications where satellites revolve in an orbit that forms a plane passing through the center of gravity of the earth, this center is called ____________geocenter
ECE Board Exam April 1998The use of telecommunication for the transmission of signals to initiate, modify or terminate functions of equivalent at a distance.Telecommand
ECE Board Exam November 1997The use of telecommunication for the transmission of signals to initiate modify or terminate
functions of equipment at a distance.Telecommand
ECE Board Exam April 1997Footprint refers to coverage area in the globe.Satellite coverage
ECE Board Exam November 1996The first commercial satelliteEarly bird
ECE Board Exam November 1996What band does VSAT first operate?C-band
ECE Board Exam April 2001Which part of transponder converts the received signal to another lower frequency?Mixer
ECE Board Exam April 1998In satellite communications, the geostationary satellites are conveniently located with respect to the equator at __________.0 degrees latitude
ECE Board Exam November 1997The Ku-band in the satellite service.14/11 GHz
ECE Board Exam April 1997Asia Sat I covers how many countries in Asia?38
ECE Board Exam November 1996Satellite engine usesion propulsion system
ECE Board Exam April 2001How do you increase or double the channel capacity of a satellite without increasing the frequency bandwidth?Re-use frequency
ECE Board Exam April 1998A satellite beam that covers almost 42.4% of earths surface.Global beam
ECE Board Exam November 1997
Receives and collects satellite signals from a broadcast satellite.Satellite disk
ECE Board Exam April 1997Sound intensity level is __________10 log I/Iref
ECE Board Exam November 1996The first passive satellite transponder.Moon
ECE Board Exam April 1998The most common application of satelliteCommunications
ECE Board Exam November 1997Radio communication operation service between mobile and land stations or between mobile stations.Mobile service
ECE Board Exam April 2001Referred to as function and/or a designed of a double conversion satellite transponder.Equipped with two mixers
ECE Board Exam November 2000How does spatial isolation technique in satellite communications avoid interference?Employment of highly directional spot-beam antennas
ECE Board Exam April 1998One of the first satellite systems catering personal based communications services scheduled for operation.Iridium system
ECE Board Exam NOvember 1997A radio communications service used in radio regulation between specified fixed points provided primarily for the safety of air navigation and for the regular efficient and economical air transport.Aeronautical Fixed Service
ECE Board Exam November 1999When do you consider that there is a satellite pass, having reference from the ground?When satellite passes at its orbit at 90 degrees from its azimuth.
ECE Board Exam April 1998Station located on an object which is beyond and is intended to go beyond the major portion of the earths athmospehere.
Space Station
ECE Board Exam November 1997An earth satellite whose period of revolution is equal the period of rotation of the earth about its axis.Geosynchronous
ECE Board Exam April 1998Known as the satellite transmitted signal from a satellite transponder to earths station.Down link
ECE Board Exam November 1997A satellite receives an uplink frequency of __________ MHz from a ground station of 3700 MHz.
ECE Board Exam April 1998What do you call the signal booster installed on the antenna dish of satellite receiver?Low noise amplifier
ECE Board Exam November 1997Which of the following refers to the smallest beam of satellite antennas radiation pattern?Spot Beam
ECE Board Exam April 1998Referred by a radio regulation as the station in the mobile service not intended to be used while in motionLand Station
ECE Board Exam November 1997Satellite system or part of a satellite system, consisting of only one satellite and the operating earth station.satellite network
ECE Board Exam April 2001Typical bandwidth of a communications satellite.500 MHz
ECE Board Exam November 2000An area on earth covered by a satellite radio beam.Footprint
ECE Board Exam April 1999A twenty four (24) satellite system used in modern telecommunications to determine a location(s) on the surface of the earth.GPS
ECE Board Exam April 2001Which type of satellite transponder improves the S/N ratio which demodulates the up-link signal to recover the baseband signals and use them to remodulate the downlink transmitter?Baseband
ECE Board Exam April 1998In shipboard satellite dish antenna system, azimuth is referred as the __________horizontal aiming of the antenna
ECE Board Exam November 1997Refers to a land station in a maritime mobile service.Coast station
ECE Board Exam November 1998__________ is known to be the first satellite capable of receiving and transmitting simultaneously.Telstar I
ECE Board Exam April 1998What is the frequency range of C-band?3.4 to 6.424 GHz
ECE Board Exam November 1997An area on the surface of the earth within the boresight of the steerable satellite beam intended to be pointed.Effective boresight area
ECE Board Exam April 1998What is the approximate percentage of earth's coverage of a geostationary satellite at zero degree elevation?42.5 %
ECE Board Exam April 2001One of the following devices in satellite transponder serves as output of the receive antenna.low noise amplifier
ECE Board Exam November 2000In a re-use frequency technique of increasing satellite channel capacity of corresponding transponders, how do you control the antenna used to prevent interference?High directional antenna
ECE Board Exam November 2000Refers to a mobile earth station in the mobile-satellite service located on board shipShip earth station
ECE Board Exam April 2001A technique in satellite communications which uses a highly directional spot-beam antenna to prevent interference from frequency sharing.Frequency re-use technique
ECE Board Exam November 2000How do you determine the satellite location in latitude and longitude measurement?Designate a point on earth directly below the satellite
ECE Board Exam November 2000A point in the satellite orbit known to be the closest location to the surface of the earth.Perigee
ECE Board Exam November 2000Which satellite transponder has the most number of mixers?Double-conversion 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Satellite
Monday, June 4, 2012
Microwave Communications (Chapter 9: Past Board Excel)
ECE Board Exam April 2001Which of the following will you avoid in the construction of a microwave station?Long horizontal runs
ECE Board Exam November 2000Radio frequency where waveguides are not used extensively.150 MHz
ECE Board Exam April 2000Term used to describe a process of approaching a desired point by directing the vehicle towards that pointHoming
ECE Board Exam November 1999A system which does not refer to a technique in reducing the propagation errors in navigational system such as multipath effectsPulse transmission
ECE Board Exam April 1999Which of the following is a navigational equipment which utilizes a ground radar system to determine the position of a plane during its approach?GCA
ECE Board Exam November 1998_____________ is referred as the difference between available power and power budget.Power margin
ECE Board Exam April 1998Space diversity transmission means transmitting and receiving on __________.two or more antennas operating on the same frequency
ECE Board Exam November 1996One of the reasons why FDM is being replaced by TDM isnoise is amplified with voice when an FDM system is used
ECE Board Exam November 1996What is the baseband frequency of standard FDM basic supergroup?312 to 552 kHz
ECE Board Exam March 1996The k-factor under normal atmospheric conditions in a microwave radio data profile calculation is equal to __________4/3
ECE Board Exam March 1996LORAN is navigational system used primarily for _________obtaining your fixed location over a large distances
ECE Board Exam April 2001What navigational system technique uses an antenna directivity to reduce an undesired multipath signals?LORAN-C
ECE Board Exam November 2000In microwave frequencies, the LOS distance is something extended through the occurrence of ____________ducting
ECE Board Exam April 2000Which of the following if not a part of the navigational radar?Duplexer------------- part of navigational radar-----------Pulser
Display unitSynchronizer
ECE Board Exam November 1999How do you account the effect of selective fading on the transmitted signal in terms of its bandwidth?more affirmative at wider bandwidth
ECE Board Exam April 1999Frequencies most affected by knife-edge refraction.VHF and UHF
ECE Board Exam April 1998Refers to an effect of selective fading.A fading effect caused by phase difference between radio wave components of the same transmission, as experienced at the receiving station.
ECE Board Exam November 1996When the clearance above the obstruction is equal to the radii of even Fresnel zones at the point of reflection the RSLis decreased
ECE Board Exam March 1996LORAN is a navigation system used primary forobtaining fixes over large distances
ECE Board Exam November 1966When the value of k increases, the effective result is _______ of the equivalent curvatures.flattening
ECE Board Exam March 1996TACAN is a navigational aid providing _________bearing and distance indication
ECE Board Exam November 1996If Ns = 250 determine the earth radius k-factor.
ECE Board Exam March 1996A one-hop, full duplex, microwave system is in a space diversity arrangement. Determine how many receivers in all are used?2
ECE Board Exam November 1996A microwave communications system space loss calculation formula is92.4 + 20 log F + 20 log D
ECE Board Exam March 1996Radio fading resulting from obstruction losses.Log normal fading
ECE Board Exam April 1998Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna.Circulator
ECE Board Exam November 1996What is the method of diversity reception where the signal is transmitted on 2 different frequencies over the same path?Frequency
ECE Board Exam November 1996What is the free space loss, in dB, between two microwave parabolic antennas 38.0 kilometer apart operating at 7.0 GHz?
ECE Board Exam November 1996Low-power radar usesIMPATT
ECE Board Exam November 2000A component of a microwave station that samples signal traveling in one direction down to the transmission line.Directional coupler
ECE Board Exam April 2000A navigational error which is caused by reflection of obstruction close to the location of navigational aid having a normal concern on directional bearing.Site error
ECE Board Exam April 1999An aircraft deviation measured by an ILS localizer.Horizontal
ECE Board Exam April 1998Which of the following systems is not used in radio detection and ranging?Amplitude modulation
----------- systems used in radio detection and ranging----------Frequency shiftFrequency modulationPulse radar
ECE Board Exam April 1997A microwave system that requires the use of repeater.Intervening system that requires the use of repeater.Distances involved are greater
ECE Board Exam November 1996Space diversity transmission means transmitting and receiving ontwo or more antennas operating on the same frequencies
ECE Board Exam April 1997RADAR meansRadio Detection and Ranging
ECE Board Exam November 2000Which band in the radio spectrum does the radio navigational system Omega transmit?VLF
ECE Board Exam November 1998Which of the following is not a common microwave application?Mobile radio
------------- common microwave application --------------RadarData transmissionSpace communications
ECE Board Exam April 1998What do you call a circuit that controls the magnetron output?Modulator
ECE Board Exam April 1997A microwave link between the earth station and the down-town terminalTerrestrial link
ECE Board Exam November 1997Two or more antennas separated by 9 wavelengths are used.Space diversity
ECE Board Exam April 2000In radio navigation, one of the following deviations of an airplane is determined by an ILS localizer.Horizontal
ECE Board Exam April 1997The advantage of periscope antenna in microwave.
Shorten waveguide link
ECE Board Exam April 2000In navigational system, one of the following indication is provided by the localizer unit of the ILS.A horizontal deviation of an airpalne from its optimum path of descent along the axis of the runway.
ECE Board Exam April 1999Referred to as the cycle time difference between the master and the slave signals to reach the receiver in the operation of loran navigational equipment.Time delay
ECE Board Exam April 1999Which of the HF marine antenna safety link is intended to be broken during the unusual movement of the ship?Weak part
ECE Board Exam April 1999What is being measured in radar theory to complete the determination of a distance to a target or object, after a high radio frequency signal is transmitted to a target?Echo time off the object to the source
RADIOWAVE…
Radiation and Wave Propagation (C5 Past board: Excel)
ECE Board Exam April 2001When the electric field is perpendicular to the surface of the earth, what is the polarization of the electromagnetic wave?Vertical
ECE Board Exam November 2000At what angle would you find the propagation direction in an xy plane . if the electric field is at 180 degrees from a reference zero degree vertical axis?90
ECE Board Exam April 2000Which of the following is referred to as the electromagnetic spectrum range of infrared signals?
0.01 millimeter – 0.70 micrometer
ECE Board Exam November 1999Which of the following conditions can cause tropospheric ducting?A stable high-pressure system
ECE Board Exam April 1999In study of wave propagation, a condition at which zero absorption of radio wave is describes asFree space medium
ECE Board Exam November 1998Determine from the following radio frequency that falls under the very high frequency band of the radio spectrum.235.50 MHz
ECE Board Exam April 1998At what distances is VHF propagation normally limited?Around 500 miles
ECE Board Exam November 1997Production of radiation by a radio transmitting stationEmission
ECE Board Exam April 1997When waves bend away from straight line of travel, it is calledRefraction
ECE Board Exam November 1996An electromagnetic wave consists ofBoth electric and magnetic fields
ECE Board Exam March 1996_________ occurs when microwave beam is at a point of grazing over an obstacle.Diffraction
ECE Board Exam April 2001Why are VHF or UHF radio signals which are transmitted towards the mountain or high structure received a distant point in different locations?Due to reflection caused by object
ECE Board Exam November 2000The medium frequency (MF) band is in the spectrum range of0.3 to 3 MHz
ECE Board Exam April 2000The highest frequency where refracted signals are returned to the eath at a desired distance with usable strength, normally referred to as the critical frequency.Maximum usable frequency
ECE Board Exam November 1999Very High (radio) Frequency in the spectrum refers to _______ waves.
Metric
ECE Board Exam 1999What is a wavefront?A fixed point in an electromagnetic wave
ECE Board Exam 1998Electromagnetic waves of frequencies arbitrarily lower than 3,000 GHz propagated in space without artificial guide.Hertzian waves
ECE Board Exam April 1998________ is a major cause of the sporadic-E condition.Sunspot
ECE Board Exam November 1997This type of transmission permits communication in the frequency range from 30 to 60 MHz over distance from about 1000 to 2000 km.Ionospheric scatterECE Board Exam April 1997Highest frequency that can be used for skywave HF communications between two given points on earth.Maximum usable frequency
ECE Board Exam March 1996The wavelength of light has no role inPolarization
ECE Board Exam March 1996Atmospheric condition is controlled byHumidityPressureTemperature
ECE Board Exam April 2001Which part of globe is considered where sporadic-E is most common?Equatorial regions
ECE Board Exam April 2000Refers to the speed of radio waves traveling through space300,000 km/sec
ECE Board Exam November 1999What is the reason why VHF radio waves can be propagated several hundred miles over oceans?Widespread temperature inversion
ECE Board Exam April 1999Region of the atmosphere where ducting occursTroposphere
ECE Board Exam November 1998Frequencies above _____ kHz, are referred to as the radio frequencies.20
ECE Board Exam April 1998A radio frequency in the Ultra High Frequency band of the radio spectrum band0.31250 GHz
ECE Board Exam November 1997The electric field lines in a plane perpendicular to the earth’s surfaceVertical polarization
ECE Board Exam April 1997Electromagnetic radiation theory was propounded byJames Clerk Maxwell
ECE Board Exam November 1996Electromagnetic waves travel at _______ in free space300,000 km/sec
ECE Board Exam March 1996When the transmitting and receiving antennas are in line-of-sight of each other, the mode of propagation is _______ wave.Space or direct
ECE Board Exam April 2000One of the following referred to as the long infrared signals in the electromagnetic spectrum range.0.010 millimeter – 1000 nanometer
ECE Board Exam April 1998What is the period of a wave?The time required to complete in one cycle
ECE Board Exam April 2001Determine the critical frequency value of an HF signal if its maximum usable frequency is 7050.50 kHz at 35 degrees incidence.
ECE Board Exam November 1997Any small element of space in the path of a wave may be considered as source of secondary wavelet.
Huygen’s principle
ECE Board Exam April 1997 / November 1997Type of transmission path that permits communication in the frequency range from 30 to 60 MHz and over distance from about 1000 to 2000 kmIonospheric scatter
ECE Board Exam April 1998What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away?Tropospheric ducting
ECE Board Exam November 1997At height of 180 km above the earth and existing during daylight.F1 layer
ECE Board Exam April 1997What is the thickest layer of the ionosphere?F2
ECE Board Exam November 1996Tropospheric scatter uses the frequencies in the _________ bandUHF
ECE Board Exam March 1996The lowest layer in the ionosphere.D
ECE Board Exam April 2001Except for ________ electromagnetic radiation or signal all others cannot be used for communication purposes. Infrared
ECE Board Exam April 2000What type of signal propagation increases the distance of reach as you select a higher frequency?HF
ECE Board Exam April 1998In radio high frequency communications, the higher the radio frequency the __________Longer it can reach
ECE Board Exam November 1997An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation.Linearly
ECE Board Exam April 1997Distance traveled by a wave in the time of one cyvle.Wavelength
ECE Board Exam March 1996In what region of the world is sporadic-E most prevalent?The equatorial regions
ECE Board Exam April 2001A possible type of propagation occurring if a weak and distorted signal from a distant station on a frequency that is closed to the maximum usable frequency is received.Sky-wave
ECE Board Exam April 2000By how many farther does the radio-path horizon distance exceed the geometric horizon?More or less 15% of the distance
ECE Board Exam April 1998What is meant by referring to electromagnetic waves as horizontally polarized?The electric field is parallel to the earth
ECE Board Exam November 1997Which of the following falls under the high frequency band of the radio spectrum?8.2345 MHz
ECE Board Exam April 1997Which region of the ionosphere is mainly responsible for long distance night time communications?F layer
ECE Board Exam April 2000What is the refractive index of air?1
ECE Board Exam November 1999Where in the spectrum band should the line of sight or direct waves is appropriate for radio transmission and reception?UHF
ECE Board Exam November 1998The extremely high frequency (EHF) band is in the radio spectrum range.3 to 30 MHz
ECE Board Exam April 1998What are electromagnetic wave?A wave consisting of an electric field and magnetic field at right angles to each other
ECE Board Exam November 1997The electric field lies in a plane parallel to the earth’s surface.Horizontal polarization
ECE Board Exam November 1997A means of beyond the line of sight propagation of microwave signalTroposcatter
ECE Board Exam April 1997What is the effective earths radius when Ns=300?
ECE Board Exam April 1997Which is atmospheric attenuation?Due to water vapor and oxygen
ECE Board Exam November 2000One of the following is not among the medium of primary communication.Radio----medium of primary communication---Free spaceWireFiber optic cable
ECE Board Exam April 2000What is the propagation condition called where scattered patches of relatively dense ionization develop seasonally at E-layer heights?Sporadic-E
ECE Board Exam November 1997What is the unit of electric field strength?V/m or N/C
ECE Board Exam April 2000Which of the following is the best time for transequatorial propagation?Afternoon or early evening
ECE Board Exam November 1999When the electric field is parallel to the surface of the earth, what is the polarization of the electromagnetic wave?Horizontal
ECE Board Exam November 2000What type of radio propagation where signal travels along the surface of the earth?Ground wave propagation
ECE Board Exam April 2000Which of the following radio communications and effects, does the auroral activity inflict?Fluttery tone on continuous wave signals
ECE Board Exam November 2000Referred to as the ionospheric layer with an average height of 225 km at night.F2 layer
REGULATORS…
CHAPTER 17 VOLTAGE REGULATORS
CHAPTER 17 VOLTAGE REGULATORS
1. The percentage change in the output voltage for a given change in the input voltage Line regulation
2. The percentage change in output voltage for a given change in load current Load regulation
3. Occurs when the internal power dissipation becomes excessive and the temperature of the device exceeds a certain value Thermal Overload
4. An electronic circuit that maintains an essentially constant output voltage with a changing input voltage or load current Regulator
5. Typical of three-terminal IC regulators that provide a fixed negative output voltage. 79XX
6. An example of a three-terminal positive regulator with an adjustable output voltage. LM317
7. Negative output counterpart of the LM317 LM337
8. A universal device that can be used with external components to provide step-up, step-down, and inverting operation 78S40
9. A voltage regulator in which the control element operate as a switch Switching regulator
10. Two basic types of linear regulators are Series and shunt
11. In linear series regulator, the control element is a transistor in _______ with the load Series
12. In linear shunt regulator, the control element is a transistor in _______ with the load. Parallel
13. A change in input voltage does not significantly affect the output voltage of a regulator. (true/false) True
14. Can be used as a current source when an application requires that a constant current be supplied to a variable load. Three-terminal regulator
15. Amplitude modulation is a ____________________process Multiplication
16. is one method used to overcome the bandwidth limitation of the telephone system so that digital data can be sent over the phone lines. FSK
SATELLITE…
Satellite Communications (Chapter 10: Past Board Exce)
ECE Board Exam April 2001What balance the gravitational pull of the earth to allow the satellite to stay on its orbit?Centripetal force
ECE Board Exam November 2000Satellite that rotates around the earth in a low-altitude elliptical or circular pattern.Nonsynchronous satellite
ECE Board Exam April 1999In a transoceanic satellite conversation, how much is the typical delay before a reply is heard?600 ms
ECE Board Exam November 1999What are the repeaters inside communications satellite known for?Transponders
ECE Board Exam April 2000Under a circular satellite orbiy, how high is a certain satellite located above the surface of the earth if the total satellite height is 9869 miles?
ECE Board Exam November 1998 Is a kind of satellite which has a period of revolution equivalent to the period if rotation of the earth about its axis. Geosynchronous satellite
ECE Board Exam April 1998A radio land station in the land mobile service.Base station
ECE Board Exam November 1997The use of telecommunication for automatic indicating or recording measurement at the distance from the measuring instrument.Telemetry
ECE Board Exam April 1997_______________ is the horizontal pointing angle of an antenna.Azimuth
ECE Board Exam November 1996How many satellite orbital slots are requested by the Philippine government from ITU?6
ECE Board Exam MArch 1996The point on satellite orbit, closest to the earth isperigee
ECE Board Exam April 2001A mobile service between base stations and land mobile stations or between land mobile stations.Mobile service
ECE Board Exam November 2000Which of the following refers to the basic component of a communication satellite receiver?Transponder
ECE Board Exam April 2000Determine from the following the basic technique used to stabilize a satellite.
Spin
ECE Board Exam November 1999A space distance iin satellite communication from the earth, to or greater than 2,000,000 kilometers is referred to as ___________.deep space
ECE Board Exam April 1999How many satellites does the GPS system consist?24 satellites
ECE Board Exam November 1999Which point on the satellite orbit is closest to the earth?perigee
ECE Board Exam November 1998Which of the following is refers to the smallest beam of a satellite antenna's radiation pattern?spot beam
ECE Board Exam April 1998A major and basic advantage for the use of klystron.Hiigh power
ECE Board Exam November 1997Station in the mobile service not intended to be used while in motion.Land station
ECE Board Exam April 1997__________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency.LNB
ECE Board Exam November 1996Collects very weak signals from a broadcast satellite.Satellite dish
ECE Board Exam March 1996It is a spacecraft replaced in orbit around the earth carrying onboard microwave receiving and transmitting equipmentsCommunications satellite
ECE Board Exam April 2001A what apogee in an elliptical orbit must a geosynchronous satellite be initially stationed before it is finally fired into its final geostationary orbit?22,300 miles
ECE Board Exam November 2000Satellite orbit around the earth are either:they are either circular or elliptical
ECE Board Exam April 2000Satellite system or part of a satellite system, consisting of only one satellite and the cooperating stations.Satellite network
ECE Board Exam November 1999A resultant effect in launching a satellite from the earth caused by both forward motion away from the earth that provides inertia tending the satellite to travel in straight line upwards and the gravitational pull towards the earth is referred to as ___________.centripetal acceleration
ECE Board Exam November 1998Which of the following refers to the first active satellite?Sputnik 1
ECE Board Exam April 1998A band where most military satellite often operate.X
ECE Board Exam November1997Known to be the first satellite capable to receive and transmit simultaneously.Telstar I
ECE Board Exam April 1997What kind of battery panels are used in some advanced satellites?Gallium arsenide solar panels
ECE Board Exam November 1996Satellite signal transmitted from a satellite transponder to earth's station.Downlink
ECE Board Exam November 1999In satellite communications where satellites revolve in an orbit that forms a plane passing through the center of gravity of the earth, this center is called ____________geocenter
ECE Board Exam April 1998The use of telecommunication for the transmission of signals to initiate, modify or terminate functions of equivalent at a distance.Telecommand
ECE Board Exam November 1997The use of telecommunication for the transmission of signals to initiate modify or terminate functions of equipment at a distance.Telecommand
ECE Board Exam April 1997Footprint refers to coverage area in the globe.Satellite coverage
ECE Board Exam November 1996The first commercial satelliteEarly bird
ECE Board Exam November 1996What band does VSAT first operate?C-band
ECE Board Exam April 2001Which part of transponder converts the received signal to another lower frequency?Mixer
ECE Board Exam April 1998In satellite communications, the geostationary satellites are conveniently located with respect to the equator at __________.0 degrees latitude
ECE Board Exam November 1997The Ku-band in the satellite service.14/11 GHz
ECE Board Exam April 1997Asia Sat I covers how many countries in Asia?38
ECE Board Exam November 1996Satellite engine usesion propulsion system
ECE Board Exam April 2001How do you increase or double the channel capacity of a satellite without increasing the frequency bandwidth?Re-use frequency
ECE Board Exam April 1998A satellite beam that covers almost 42.4% of earths surface.Global beam
ECE Board Exam November 1997Receives and collects satellite signals from a broadcast satellite.Satellite disk
ECE Board Exam April 1997Sound intensity level is __________10 log I/Iref
ECE Board Exam November 1996The first passive satellite transponder.Moon
ECE Board Exam April 1998The most common application of satelliteCommunications
ECE Board Exam November 1997Radio communication operation service between mobile and land stations or between mobile stations.Mobile service
ECE Board Exam April 2001Referred to as function and/or a designed of a double conversion satellite transponder.Equipped with two mixers
ECE Board Exam November 2000How does spatial isolation technique in satellite communications avoid interference?Employment of highly directional spot-beam antennas
ECE Board Exam April 1998One of the first satellite systems catering personal based communications services scheduled for operation.Iridium system
ECE Board Exam NOvember 1997A radio communications service used in radio regulation between specified fixed points provided primarily for the safety of air navigation and for the regular efficient and economical air transport.Aeronautical Fixed Service
ECE Board Exam November 1999When do you consider that there is a satellite pass, having reference from the ground?When satellite passes at its orbit at 90 degrees from its azimuth.
ECE Board Exam April 1998
Station located on an object which is beyond and is intended to go beyond the major portion of the earths athmospehere.Space Station
ECE Board Exam November 1997An earth satellite whose period of revolution is equal the period of rotation of the earth about its axis.Geosynchronous
ECE Board Exam April 1998Known as the satellite transmitted signal from a satellite transponder to earths station.Down link
ECE Board Exam November 1997A satellite receives an uplink frequency of __________ MHz from a ground station of 3700 MHz.
ECE Board Exam April 1998What do you call the signal booster installed on the antenna dish of satellite receiver?Low noise amplifier
ECE Board Exam November 1997Which of the following refers to the smallest beam of satellite antennas radiation pattern?Spot Beam
ECE Board Exam April 1998Referred by a radio regulation as the station in the mobile service not intended to be used while in motionLand Station
ECE Board Exam November 1997Satellite system or part of a satellite system, consisting of only one satellite and the operating earth station.satellite network
ECE Board Exam April 2001Typical bandwidth of a communications satellite.500 MHz
ECE Board Exam November 2000
An area on earth covered by a satellite radio beam.Footprint
ECE Board Exam April 1999A twenty four (24) satellite system used in modern telecommunications to determine a location(s) on the surface of the earth.GPS
ECE Board Exam April 2001Which type of satellite transponder improves the S/N ratio which demodulates the up-link signal to recover the baseband signals and use them to remodulate the downlink transmitter?Baseband
ECE Board Exam April 1998In shipboard satellite dish antenna system, azimuth is referred as the __________horizontal aiming of the antenna
ECE Board Exam November 1997Refers to a land station in a maritime mobile service.Coast station
ECE Board Exam November 1998__________ is known to be the first satellite capable of receiving and transmitting simultaneously.Telstar I
ECE Board Exam April 1998What is the frequency range of C-band?3.4 to 6.424 GHz
ECE Board Exam November 1997An area on the surface of the earth within the boresight of the steerable satellite beam intended to be pointed.Effective boresight area
ECE Board Exam April 1998What is the approximate percentage of earth's coverage of a geostationary satellite at zero degree elevation?42.5 %
ECE Board Exam April 2001One of the following devices in satellite transponder serves as output of the receive antenna.low noise amplifier
ECE Board Exam November 2000In a re-use frequency technique of increasing satellite channel capacity of corresponding
transponders, how do you control the antenna used to prevent interference?High directional antenna
ECE Board Exam November 2000Refers to a mobile earth station in the mobile-satellite service located on board shipShip earth station
ECE Board Exam April 2001A technique in satellite communications which uses a highly directional spot-beam antenna to prevent interference from frequency sharing.Frequency re-use technique
ECE Board Exam November 2000How do you determine the satellite location in latitude and longitude measurement?Designate a point on earth directly below the satellite
ECE Board Exam November 2000A point in the satellite orbit known to be the closest location to the surface of the earth.Perigee
ECE Board Exam November 2000Which satellite transponder has the most number of mixers?Double-conversion 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Satellite
Wednesday, September 7, 2011
SATELLITE MULTIPLE ACCESSING ARRANGEMENTS (c26)
CHAPTER 26SATELLITE MULTIPLE ACCESSING ARRANGEMENTS
1)Also called as Multiple Destination, It implies that more than one user has access to one or more radio channels within a satellite communications channel. Multiple AccessingMultiple Accessing Arrangement: Frequency-division multiple accessing (FDMA) Time-division multiple accessing (TDMA) Code-division multiple accessing (CDMA)
2)A given number of the available voice-band channels from each earth station are assigned a dedicated destination.
Pre-assignment(dedicated) 3)Voice channels are assigned on an as-needed basis.Demand Assignment 4)The method of assigning adjacent channels different electromagnetic polarizations and is possible by using orthogonal polarization and spacing adjacent channels 20 MHz apart.Frequency Reuse 5)Eskimo word meaning “little brother”.Anik 6)Domestic Satellites operated by Telsat Canada.Anik-E communications Satellite 7)A method of multiple accessing where a given RF bandwidth is divided into smaller frequency bands.FDMA 8)Multiple channel per carrier formats assigned and remain fixed for a long Period of time.Fixed-Assignment, Multiple Access (FAMA)
9)Assigning carrier frequency on temporary basis using a statistical assignment process.Demand-AssignmentMultiple Access 10)An acronym for Single-channel-per-carrier PCM multiple Access Demand-assignment Equipment.SPADE 11)Stands for Single-Carrier-Per-Channel.SCPC 12)A time division-multiplexed transmission that is frequency division multiplexed.Common Signaling Channel (CSC) 13)The predominant Multiple-access method of time-division multiplexing digitally modulated carriers between participating earth stations within a satellite network through a common satellite transponder.TDMA 14)An RF-to-RF repeater that simply receives the earth station transmissions, amplifies them, and then re-transmit them in a downlink beam that is received by all other
participating station.Transponder 15)It is where transmissions from all earth stations are synchronized.Reference Burst 16)It is where all receiving stations recover a frequency and phase coherent carrier for PSK demodulationCarrier Recovery Sequence (CRS) 17)An acronym for Conference of European Postal and Telecommunications Administrations, is commonly used TDMA frame format for digital satellite systemCEPT 18)Sometimes referred to as Spread-Spectrum Multipleentire allocated bandwidth Access, the transmissions can spread throughout theCode-Division Multiple Access (CDMA)
19)A unique binary word that each earth station’s transmissions are encoded.Chip Code 20)It compare two signals and recover the original data.Correlator 21)It assigns an individual terrestrial channel (TC) to a particular satellite channel (SC) for the duration of the call.Digital non interpolated Interface 22)It assigns a terrestrial channel to a satellite channel only when speech energy is present on the TC.Digital Speech Interpolated Interface 23)A form of analog channel compression that has been used for sub oceanic cables for many years.Time-Assignment Speech Interpolation (TASI) 24)The art or science of plotting, ascertaining or directing the course of movements, in other words, knowing where you are and being able to find your way around.Navigation 25)It is the most ancient and rudimentary method of navigation and simply continuing to travel about until you reach your destination, assuming of course that you have one.Wandering 26)Earliest effective means of navigation wherein direction and distance are determined from precisely timed sightings of celestial bodies, including the stars and moon.
Celestial Navigation 27)Method of navigation by means of fixing a position and direction with respect to familiar, significant landmarks such as railroad tracks, water towers, barns, mountains and bodies of water.Piloting
28)A navigation technique that determines position by extrapolating a series of measured velocity increments.Dead Reckoning 29)The term derived from the word “deduced” and not necessarily from the fate of the people who used the technique.Dead 30)He used dead reckoning successfully in 1927 during his historic 33-hour transatlantic journey.Charles Lindbergh 31)She attempted to make the first around-the-world in 1937 using the dead reckoning technique.Amelia Earhart 32)Navigation technique wherein the position is deter-mined by measuring the travel time of an electro magnetic wave as it moves from a transmitter to a receiver.Radio Navigation 33)A radio Navigation system for terrestrial surface broadcast.Decca 34)Radio Navigation system that provide global coverage and terrestrial surface broadcast.Omega 35)Also a terrestrial surface broadcast.LORAN 36)Low-orbit satellite broadcast, provides global coverage.Navy Transit GPS 37)Medium-orbit satellite broadcast also provides global coverage.Navstar GPS 38)Means of radio navigation in which receivers acquire Coded signals from two pairs of high-powered, land based transmitters whose locations are precisely known.
LORAN 39)An acronym for Navigation System with Time and Ranging.Navstar
40)An abbreviation for Global Positioning System.GPS Two levels of service or accuracy: Standard Positioning Service Precise Positioning Service
41)A satellite-based open navigation system which simply means that it is available to anyone equipped with a GPS receiver. Navstar GPSConsists of three segments: a space segment a ground control segment user segment
42)It is when was the Navstar declared as fully operational by the U.S. Air Force Space Command.April 27, 1995 43)It was completed in 1994 and is maintained by the United States Air Force.Navstar Satellite System 44)A positioning and timing service that is available to all GPS users on a continuous, worldwide basis with no direct change.Standard Positioning Service 45)Sometimes called Space Segment, consists of 24operational satellites revolving around Earth in six orbital planes approximately 60° apart with four satellites in each plane.Satellite Segment 46)It produces highly accurate timing signals for satellites.Cesium Atomic Clock 47)A unique integer number that is used to encrypt the signal from that satellite.Pseudorandom Noise (PRN) Code Number 48) A term associated with a table showing the position of a heavenly body on a number dates in a regular sequence, in essence, an astronomical almanac.Ephemeris
49)Error in the receiver’s clock which affects the accuracy of the time-difference
measurement.Clock Bias Error 50)The Navstar control segment.It consists of : Fixed-location ground based monitor stations Master Control Station uplink transmitterOperational Control System 51)It makes standard GPS more accurate. It works by canceling out most of the natural and man-made errors that creep into normal GPS measurements.Differential GPS0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Satellite, Tomasi
SATELLITE COMMUNICATIONS (c25 Tomasi)
CHAPTER 25SATELLITE COMMUNICATIONS
1)A celestial body that orbits around a planet.Satellite2)Man-made satellites that orbit earth, providing a multitude of communication functions to a wide variety of consumers, including military, governmental, private and commercial subscriber.Communications Satellites3)A satellite radio repeater which a satellite may have many.Transponder Consists of :input Bandlimiting device (BPF)input low-noise amplifier (LNA)frequency translatorlow level amplifieroutput bandpass filter
4)It consists of one or more satellite space vehicles, a ground-based station to control the operation of the system, and a user network of earth stations that provides the interface facilities for the transmission and reception of terrestrial communications traffic through the satellite system.Satellite System5)It includes control mechanism that support the payload operation.Bus
6)The actual user information conveyed through the system.Payload
7)A type of satellite wherein it simply “bounces” signals from one place to another.Passive Reflector8)A natural satellite of Earth, visible by reflection of sunlight having a slightly elliptical orbit.Moon9)Used by passive satellites for tracking and ranging purposes.Radio Beacon Transmitters10)Launched by Russia, the first active earth satellite in 1957. It transmitted telemetry for 21 days.Sputnik I11)A type of satellite capable of receiving, amplifying, reshaping, regenerating and retransmitting information.Active Satellite12)Satellite launched by U.S., it transmitted telemetry information for nearly five months.Explorer I13)Satellite launched by NASA in 1958, a 150-pound conical-shaped satellite. It was the first artificial satellite used for relaying terrestrial communications.Score14)The first active satellite to simultaneously receive and transmit radio signals.Telstar I15)Launched in 1963, and was used for telephone television, facsimile and data transmission and accomplished the first successful transatlantic video transmission.Telstar II16)Launched in February 1963, was the first attempt to place a geosynchronous satellite into orbit.Syncom I
17)It was the first commercial telecommunications satellite. It launched from Cape Kennedy in 1965 and used two transponders. Also called as Early Birds.It stands for International Telecommunications Sate-llite.Intelsat I18)Domestic satellite launched by former Soviet Union in 1966. It means “lighting”.Molya19)A German astronomer who discovered the laws thatgoverns satellite motion.Johannes Kepler20)It may be simply stated as: The planets move in ellipses with the sun at one focus The line joining the sun and the planet sweeps out equal intervals of time.The square of the time of revolution of a planet divided by the cube of its mean distance from the sun gives a number that is the same for all planets.Kepler’s Law21)The point in an orbit closest to earthPerigee
22)The point in an orbit farthest from the earth.Apogee23)It states that the square of the periodic time of orbit is proportional to the cube of the mean distance between the primary and the satellite.Harmonic Law24)High-altitude earth-orbit satellites operating primarily in the 2-GHz to 18 GHz frequency spectrum with orbits Satellite 22,300 miles above earth’s surface.Geosynchronous SatelliteAdvantages of Geosynchronous Satellite:It remain almost stationary in respect to a given earth station.Available to earth within their shadows 100% of the time.No need to switch from one geosynchronous satellite to another as they orbit overheadThe effects of Doppler shift are negligibleDisadvantages of geosynchronous Satellite:It requires sophisticated and heavy propulsion device onboard to keep them in a fixed orbitMuch longer propagation delaysRequires higher transmit power and more sensitive receivers because of the longer distances and greater path loss.High precision spacemanship is required.25)The angle between the earth’s equatorial plane and the orbital plane of a satellite measured counter clockwise at the point in the orbit where it crosses the equatorial plane traveling from south to north called the ascending node.Angle of Inclination26)The point where the polar or inclines orbit crosses the equatorial plane travelling from north to southDescending Node27)The line joining the ascending and descending nodeLine of Nodes28)It is when the satellite rotates in an orbit directl above the equator, usually in a circular path.Equatorial Orbit
29)It is when the satellite rotates in path that takes over the North and the South poles in an orbit that is close to earth and passes over and very close to both the North and South Poles.Polar Orbit30)The noise power normalized to a 1 Hz bandwidth, or the noise power present in a 1Hz bandwidthNoise Density31)It identifies the system parameters and is used to determine the projected carrier-to-noise ratio and energy Bit-to-noise density ratio at both the satellite and earth station receivers for a given modulation scheme.Link Budget0 comments Email This BlogThis! Share to Twitter Share to Facebook
Labels: Communications, Satellite, Tomasi
Tuesday, February 1, 2011
Satellite Communications (Blake C20)
TRUE/FALSE
1. Communications satellites could be just passive reflectors.
ANS: T
2. A typical communications satellite can cover half of the earth's surface.
ANS: F
3. Most communications satellites are in a geosynchronous orbit.
ANS: T
4. Most communications satellites are in a geostationary orbit.
ANS: T
5. "Geostationary" means the same thing as "geosynchronous".
ANS: F
6. A geosynchronous orbit is about 3,600 km above the equator.
ANS: F
7. Signals from satellites in a geosynchronous orbit suffer a great deal of free-space attenuation.
ANS: T
8. It is easier to reach a geosynchronous satellite from higher northern latitudes.
ANS: F
9. At the frequencies satellites use, the ionosphere has negligible effect.
ANS: T
10. The closer a satellite is to earth, the faster the velocity it needs to stay in orbit.
ANS: T
11. In the Northern Hemisphere, an antenna must face south to reach a satellite.
ANS: T
12. You cannot communicate with a geosynchronous satellite from the Southern Hemisphere.
ANS: F
13. You cannot communicate with a geosynchronous satellite from the South Pole.
ANS: T
14. Typically, ground antennas must be movable to "track" a geosynchronous satellite.
ANS: F
15. The azimuth and elevation needed for an antenna to "see" a certain satellite depend on the location of the antenna on the ground.
ANS: T
16. The power in the uplink signal to a typical communications satellite is in the range of 50 to 240 watts.
ANS: F
17. The power in the downlink signal from a typical communications satellite is in the range of 10 to 250 watts per transponder.
ANS: T
18. The EIRP of a satellite depends on the gain of its antenna.
ANS: T
19. The EIRP of a satellite is the same anywhere reception is possible.
ANS: F
20. It takes over half a second for a signal to go from point A to point B and back again via geostationary satellite.
ANS: T
21. The useful life of a communications satellite is over when it runs out of fuel.
ANS: T
22. The maximum useful life of a communications satellite is about three years.
ANS: F
23. Using the C band for satellites may conflict with terrestrial microwave communications.
ANS: T
24. Ku-band antennas can be smaller than C-band antennas.
ANS: T
25. Conventional analog satellite transponders cannot be used with digital data signals.
ANS: F
26. It is possible to transmit signals from one satellite to another.
ANS: T
27. In practice, the beamwidth of a parabolic reflector is independent of its diameter.
ANS: F
28. Communications satellites are particularly well suited to long-distance telephony.
ANS: F
29. With TDMA, more than one hundred earth stations can use the same satellite transponder.
ANS: T
30. LEO communications satellite systems have been a great commercial success.
ANS: F
MULTIPLE CHOICE
1. The height of the geosynchronous orbit above the equator is about:a. 3,578 km c. 357,800 kmb. 35,780 km d. depends on satellite velocity
ANS: B
2. The high and low points of a satellite's orbit are called, respectively,:a. apogee and perigee c. uplink and downlinkb. perigee and apogee d. downlink and uplink
ANS: A
3. The area on the earth that is "covered" by a satellite is called its:a. earth station c. footprintb. downlink d. plate
ANS: C
4. The velocity required to stay in orbit:a. is constantb. is zero (freefall)c. is lower close to the earth than far from the earthd. is higher close to the earth than far from the earth
ANS: D
5. An antenna is aimed by adjusting the two "look angles" called:a. azimuth and elevation c. declination and elevationb. azimuth and declination d. apogee and perigee
ANS: A
6. The power per transponder of a typical Ku-band satellite is in the range:a. 5 to 25 watts c. 500 to 2500 wattsb. 50 to 250 watts d. depends on its orbit
ANS: B
7. The power level for an earth station to transmit to a satellite is on the order of:a. 101 watts c. 103 wattsb. 102 watts d. 104 watts
ANS: C
8. The "payload" on a communications satellite consists of:a. transponders c. solar cellsb. batteries d. all of the above
ANS: A
9. "Station-keeping" refers to:a. antenna maintenance c. orbital adjustmentsb. power-level adjustments d. none of the above
ANS: C
10. DBS stands for:a. decibels of signal c. direct-broadcast systemb. down-beam signal d. direct-broadcast satellite
ANS: D
11. LNA stands for:a. low-noise amplifier c. low-noise amplitudeb. low north angle d. low-noise array
ANS: A
12. A reduction in TWT power for linearity is called:a. backdown c. power-downb. backoff d. EIRP drop
ANS: B
13. TVRO stands for:a. television receive only c. television remote originb. television repeater only d. none of the above
ANS: A
14. TDMA stands for:a. transponder-directed multiple antennas c. time-division multiple access
b. television distribution master antenna d. transmit delay minimum aperture
ANS: C
15. VSAT stands for:a. video satellite c. very small antenna terminalb. video signal antenna terminal d. very small aperture terminal
ANS: D
16. On the uplink from a terminal, a VSAT system uses:a. high power to a small antenna c. low power to a large antennab. low power to a small antenna d. LEO satellites
ANS: B
17. A typical VSAT system is configured as a:a. star c. ringb. mesh d. repeater
ANS: A
18. LEO stands for:a. long elliptic orbit c. lateral earth orbitb. low-earth orbit d. longitudinal earth orbit
ANS: B
19. For real-time communication, LEO systems require:a. a constellation of satellites c. very high powerb. tracking dish antennas d. all of the above
ANS: A
20. The frequency bands used by Ku-band satellites are:a. 4 GHz and 6 GHz c. 20 GHz and 30 GHzb. 12 GHz and 14 GHz d. none of the above
ANS: B
COMPLETION
1. A satellite in geosynchronous orbit takes ____________________ hours to complete one orbit.
ANS: 24
2. The ____________________ is the signal path from the earth station to the satellite.
ANS: uplink
3. The ____________________ is the signal path from the satellite to the earth station.
ANS: downlink
4. A satellite in a ____________________ orbit appears to stay directly above one spot on the equator.
ANS: geostationary
5. Non-geostationary satellites are sometimes called ____________________ satellites.
ANS: orbital
6. A geosynchronous orbit is about ____________________ km above the earth.
ANS: 35,780
7. A ____________________ is an outline of the area on the earth's surface that a satellite broadcasts to.
ANS: footprint
8. All satellite orbits are ____________________ in shape.
ANS: elliptical
9. The ____________________ is the distance of a satellite's closest approach to the earth.
ANS: perigee
10. The ____________________ is a satellite's farthest distance from the earth.
ANS: apogee
11. An antenna's ____________________ is its angular direction between east and west.
ANS: azimuth
12. An antenna's ____________________ is its vertical angle with respect to the earth's surface.
ANS: elevation
13. An antenna's ____________________ is the angle by which it is offset from the earth's axis.
ANS: declination
14. Satellites using the ____________________ band operate on 12 GHz.
ANS: Ku
15. The time for a signal to make a round trip via satellite is about ____________________ milliseconds.
ANS: 500
16. A ____________________ is a type of repeater used on communications satellites.
ANS: transponder
17. Both the gain and the beamwidth of a dish antenna depend on its ____________________.
ANS: diameter
18. VSAT systems commonly use a ____________________ network configuration.
ANS: star
19. To date, LEO satellite systems have been a financial ____________________.
ANS: failure
20. C-band antennas are ____________________ than Ku-band antennas.
ANS: larger
SHORT ANSWER
1. A receiving antenna with a gain of 44.4 dBi looks at a sky with a noise temperature of 15 K. The loss between the output of the antenna and the input of the LNA is 0.4 dB, and the LNA has a noise temperature of 40 K. Calculate the G/T.
ANS: 25 dB
2. A receiver has a noise figure of 1.7 dB. Find its equivalent noise temperature.
ANS: 139 K.
3. A receiving antenna with a G/T of 25 dB is used to receive signals from a satellite 38,000 km away. The satellite has a 100-watt transmitter and an antenna with a gain of 30 dBi. The signal has a bandwidth of 1 MHz at a frequency of 12 GHz. Calculate the C/N at the receiver.
ANS: 38 dB
SEMICONDUCTOR…
CHAPTER 1 INTRODUCTION TO SEMICONDUCTORS
CHAPTER 1INTRODUCTION TO SEMICONDUCTORS
1. The forces between the opposite charges form an Electric field
2. What is the least accurate approximation of a diode that can be represented by a simple switch? The Ideal diode model
3. The best conductors are the _________ element materials Single 4. Occurs when a conduction-band electron loses energy and falls back into a hole in the valence band Recombination
5. Refers to the fact that the region near the pn junction is depleted of charge carriers due to diffusion across the junction. Depletion
6. The condition that essentially prevents current through the diode Reverse bias
7. The absence of an electron in the valence band of an atom Hole
8. The removal or addition of an electron from or to a neutral atom so that the resulting atom has a net positive or negative charge. Ionization
9. The resistance of a forward-biased diode is called the Dynamic or ac resistance
10. One that has no impurities Intrinsic crystal
11. Most good insulators are ________ rather than the single-element materials Compounds
12. To increase the number of conduction-band electrons in intrinsic silicon, ___________ impurity atoms are added. Pentavalent
13. To increase the number of holes in intrinsic silicon, __________ impurity atoms are needed. Trivalent
14. A ___________ material consists of silicon atom and trivalent impurity atoms such as boron p-type
15. A silicon material that consists of silicon atoms and pentavalent impurity atoms such as antimony. N- type
16. What is the value of the reverse current of practical diode model? 0
17. Semiconductor atoms bond together in a symmetrical pattern to form a solid material called ___________. crystal
TELEPHONE…
CELLULAR TELEPHONE SYSTEM (C20 Tomasi)
CHAPTER 20CELLULAR TELEPHONE SYSTEM
1)Stands for Standard Cellular Telephone ServiceCTS
2)An acronym for Personal Communications System.PCS
3)Stands for Personal Communications Satellite System.PCSS
4)An acronym for Advanced Mobile Telephone System.AMPS
5)Proposed the cellular telephone concept in 1971.Bell Telephone Laboratories
6)A standard cellular telephone service (CTS) initially placed into operation on Oct. 13, 1983.AMPS
7)It was used by AMPS cellular telephones with a usable audio-frequency band from 300 Hz to 3 KHz and a maximum frequency deviation of + 12 KHz for 100% modulation.Narrowband Frequency Modulation (NBFM)
8)Correspond to an approximate bandwidth of 30 KHz.Carson’s Rule
9)A transmission with simultaneous transmission in both direction. Full Duplex (FDX) or Duplexing
10)It is used in AMPS and occurs when two distinct frequency bands are provided to each user.Frequency-division Duplexing
11)A special device used in each mobile unit to allow simultaneous transmission and reception on duplex channels.Duplexer
12)Transmissions from base station to mobile units.Forward Links
13)Transmissions from mobile units to base stations.Reverse Links
14)Another name for forward links.
Down Links
15)Another term for reverse link.Uplink
16)Additional frequencies of 10 MHz to the original40 MHz band which increased the number of simplex channels by 166 for a total of 832 (416 Full duplex)Expanded Spectrum
17)Specified frequencies in a small geographic area.Cellular Geographic Serving Areas (CGSA)
18)Defines geographic areas used by marketing agencies.Standard Metropolitan Statistical Area
19)A technique used by standard telephone subscriber to access the AMPS system.Frequency Division Multiple Access
20)A 34 bit binary code which in the U.S. represents the standard 10-digit telephone number.Mobile Identification Number (MIN)
21)A 34 bit binary code permanently assigned to each mobile unit.Electronic Serial Number (ESN)
22)Stands for Vehicle Identification Number.VIN
23)An acronym for Network Interface Card.NIC
24)A four bit code which indicates whether the terminal has access to all 832 AMPS channel or only 666.Station Class Mark (SCM)
25)A 15 bit binary code used by FCC to an operating company when it issues it a license To provide AMPSSystem Identifier (SID)
26)It is one of the three analog frequencies (5970 Hz, 6000 Hz, or 6030 Hz) that helps mobile system distinguish one base station from a neighboring base station.Supervisory Audio Tone (SAT)
27)One of four binary codes, also helps mobile system distinguish one base station from a neighboring base station.Digital Color Code (DCC)
28)One set of channels dedicated for exchanging control information between mobile units and base stations.Control Channels
29)Also termed as Voice channel, used for propagating actual voice conversations orsubscriber data.User Channel
30)Another name of control channels.Setup or Paging Channel
31)Sometimes called as Camped.Locked
32)A sequence of alternating 1s and 0s.Dotting Scheme
33)A unique sequence of 1s and 0s that enables the receiver to instantly acquire synchronization.Synchronization Word
34)It controls or command mobile units to do a particular task when the mobile unit has not been assigned a voice channel.Mobile Station Control Messages
35)It is used to indicate the current status of the reversecontrol channel.Busy-idle Bits
36)It contains the following:System parameter overhead messagesglobal action overhead messagescontrol filter messagesTypical mobile-unit control messages:Initial voice channel designation messagesdirected retry messagesalert messageschange power messagesOverhead Message
37)Transmitted at a 10-kbps rate.Control data includes:
page responsesaccess requestregistration requestsControl Data
38)Transmission of voice.Blank
39)Data transmission.Burst
40)The entity of SS7 interoffice protocol that distinguishes the physical components of the switching network.Switching Network:Signal Service PointSignal Control PointSignal Transfer PointIntelligent Network
41)A family of mobile or portable radio comunications services which provides servIces to the individuals and business and is integrated with a variety of competing networks.Differences in PCS and cellular telephone system:Smaller Sizeall digitaladditional featuresPersonal Communications System (PCS)
42)Acronym for Personal Communications Network.PCN
43)It is assigned to everyone which is stored the on the SS7 network.Personal Telephone Number
44)It determines where and how the call should be directed.Artificial Intelligence Network (AIN)
45)A database that stores information about the user,including home subscription information and what supplementary services the user issubscribed to.Home Location Register (HLR)
46)A database that stores information pertaining to theidentification and type of equipment that exists in the mobile unit.
Equipment Identification Registry (EIR)
47)It allows all calls to pass through the network to the subscriber except for a minimalnumber of telephone numbers that can be blocked.Available Mode
48) The PCS equivalent of caller ID.Screen Mode
49)All calls except those specified by the subscriber are automatically forwarded to a forwarding destination without ringing the subscriber’s handset.Private Mode
50)No calls are allowed to pass through to the subscriber.Unavailable Mode
51)PCS operating in the 1900 MHz range.PCS 1900
52)Interference avoidance scheme which uses voice companding to provide syntheticvoice channel quieting.Interference (MRI)
53)A narrowband AMPS system that increased the capacity of the AMPS system in largecellular market.N-AMPS
54)It is developed with the intent of supporting a higher user density within a fixedbandwidth frequency spectrum.United States Digital Cellular
55)Cellular telephone systems that use digital modulation.Digital cellular
56)Allows one mobile unit to use a channel at the same time by further dividingtransmissions within each cellular channel.Time-division Multiple Accessing (TDMA)
57)A database that stores information about subscriber in a particular MTSO serving area, such as whether the unit is on or off
Visitor Location Register(VLR)
58)Technique used that allows more mobile-unit subscribers to use a system at virtually the Same time within a given geographical area.Time-Sharing Channels
59)It stands for Electronics Industries Association and Telecommunications Industry Association.EIA/TIA
60)It specifies that a mobile station complying with the IS-54 standard must be capable of operating in either the analog AMPS or the digital (USDC) mode for voice transmissions.Dual Mode
61)It is often called North American Time Division Multiple Accessing.IS-136.2
62)It was introduced to provide PSK rather than FSK on dedicated USDC control channels to in crease the control data rates and provide additional specialized services such as paging and short messaging between private mobile user groups.IS-54 Rev.C
63)Allows for brief paging-type messages and Short e-mail messages that can be read on the mobile phone’s display and entered using the keypad.Short Message Service
64)It was developed to provide a host of new features and services, positioning itself in a competitive within the newer PCS systems.IS-136
65)It is used by mobile units to request access to the cellular telephone system. It is aunidirectional channel specified for transmissions from mobile-base units only.Random Access Channel (RACH)
66)It is used to transmit information from base stations to specific mobile stations.SMS point-to-point Paging and access response Channel (SPACH)
67)It is dedicated to delivering pages and orders.It transmit :paging messages
message-waiting messagesuser alerting messagescall history count updatesshared secret data updatesPaging Channel (PCH)
68)A logical subchannel of SPACH used to carry assignments to another resource or other responses to the mobile station’s access attempt.Access Response Channel (ARCH)
69)It is used to deliver short point-to-point messages to a specific mobile station.SMS Channel (SMSCH)
70)It refers to : F-BCCH, E-BCCH and S-BCCH logical sub channels.Channel (BCCH)
71)Broadcasts digital control channel structure parameters.Fast Broadcasts Control channel (F-BBCH)
72)Carries less critical broadcast information than F-BCCH intended for mobile units.Extended Broadcasts Control Channel (E-BBCH)
73)Individual mobile units. A logical channels used for sending short messages.SMS Broadcasts Control channel (F-BBCH)
74)Stands for Digital speech interpolation.DSI
75)Carries digital voice information and consists of RDTC and FDTC.Digital Traffic Channel(DTC)
76)It consists of an eight bit digital voice color code number between 1 and 255 appended with four Coded Digital VerificationColor Code
77)Mobile-assisted handoff.MAHO78)A blank-and burst type of transmission that replaces digitized speech information with control and supervision messages with in a subscriber’s time slot.Fast Associated Control Channel (FACCH)
79)A special speech coder.Vector sum exciter linear predictive (VSLP)
80)A special microprocessor that is implemented on the telephone handset.Digital Signal Processor (DSP)
81)They are transmitted when a mobile unit begins operating in a larger diameter cell.Shortened Burst
82)An access method used with standard analog AMPS which use frequency channelization approach to frequency spectrum management.FDMA
83)It allows users to differentiate from one another by a unique code rather than a frequency or time assignment.Code Division Multiple Accessing (CDMA)
84)Stands for Qualcom 9600bps Code-Excited Linear Predictive coder.QCELP
85)The concept is to break the message into fixed sized blocks of data with each block transmitted in sequence except on a different carrier.Frequency Hopping
86)high bit pseudorandom code is added to a low-bit rate information signal to generate a high bit rate pseudorandom signal closely resembling noise that contains both the original data signal and the pseudo random code must be known.Direct-Sequence
87)It is a study group which is sometimes referred to as Pan-European cellular system. This is now known as the Global System for MobileCommunications.Classification of GSM telephone services:Bearer Servicesteleservicessupplementary servicesThree primary subsystem of GSM:Base Station SubsystemNetwork Switching SubsystemOperational Support SubsystemGroupe Special Mobile (GSM)
88)All-digital data Network.
Integrated Services Digital Network (ISDN)
89)Sometimes known as radio subsystem, provides and manages radio frequency transmission paths between mobile units and the mobile switching center (MSC)Base Station Subsystem (BSS)
90)It manages switching functions for the system and allows MSCs to communicate with other telephone networks.Network Switching Subsystem (NSS)
91)The available forward and reverse frequency bands are subdivided into 200 KHz wide voice channels.Absolute Radio-Frequency Channel Numbers (ARFCN)
92)It provides the vehicle for a new generation of wireless telephone services called Personal Communications Satellite System (PCSS)Mobile Satellite Systems (MSS)
93)It uses low earth-orbit (LEO) and medium earth orbit and MEO thar communicates diretly with small, low-powered mobile telephone units.key providers in PCSS market:American Mobile SatelliteCommunications (AMSC)CelsatComsatConstellation Communications (ARIES)Ellipsat (Ellipso)INMARSATLEOSATLoral/qualcomm (global star)TMI communicationsTWR (Odysse)Iridium LLCPersonal Communications Satellite System (PCSS)94)An international consortium owned by a host of prominent companies, agencies and governments.Iridium LC
95)The largest commercial venture undertaken in the history of the world.Iridium Project
96)A satellite based wireless personal communications network designed to permit a wide range of mobile telephone services, including voice, data, networking,facsimile and paging.Iridium
97)FCC issued a report and order Dockett # 92-166 defining L band frequency sharing for subscriber units in the 1616 MHZ to 1626.5 MHz band.October 14, 1994
98)L-band subscriber-to-satellite voice links.1.616 GHz to 1.6265 GHz
99)Ka-band gateway downlinks.19.4 GHz to 19.6 GHz
100)Ka-band gateway uplinks29.1 GHz to 29.3 GHz
101)Ka-intersatellite cross-links23.18 GHz to 23.38 GHz
TELEVISION…
Television (Blake C19)
TRUE/FALSE
1. Video systems form pictures by a scanning process.
ANS: T
2. The NTSC system is used in North America.
ANS: T
3. The NTSC system is used in Europe.
ANS: F
4. The NTSC system is used in Japan.
ANS: T
5. The PAL system is no longer used in much of the world.
ANS: F
6. The SECAM system is used in Europe.
ANS: T
7. In North America, TV uses 60 frames a second.
ANS: F
8. NTSC systems use an interlaced scan.
ANS: T
9. The standard TV aspect ratio is 5:3.
ANS: F
10. The electron beam in a TV CRT is blanked during horizontal retrace.
ANS: T
11. The electron beam in a TV CRT is blanked during vertical retrace.
ANS: T
12. The standard analog TV signal is called composite video.
ANS: T
13. A few commercial TV stations broadcast RGB video.
ANS: F
14. Most color monitors for personal computers use RGB video.
ANS: T
15. The luminance signal controls the brightness of a scan line.
ANS: T
16. The standard synchronization for TV is called positive sync.
ANS: F
17. The sync pulses are said to be "blacker than black".
ANS: T
18. The negative peak of a video signal occurs during a sync pulse.
ANS: T
19. The peak video signal occurs at the blanking level.
ANS: F
20. The duration of the vertical blanking pulse identifies which picture field is present.
ANS: F
21. Closed-caption signals can be sent during the vertical blanking time.
ANS: T
22. Horizontal and vertical resolution in a TV system are determined in the same way.
ANS: F
23. The resolution seen by a viewer depends to a certain extent on the TV receiver.
ANS: T
24. Horizontal resolution is equal to the number of visible scan lines.
ANS: F
25. Resolution is proportional to bandwidth.
ANS: T
26. Because of the way people perceive color, any color can be made with red, green, and blue.
ANS: T
27. NTSC color television is not compatible with NTSC monochrome television.
ANS: F
28. In an NTSC color TV system, luminance is derived from the RGB signals.
ANS: T
29. Horizontal resolution for color in NTSC is much less than it is for luminance.
ANS: T
30. NTSC uses a suppressed-carrier system to add color information to the video signal.
ANS: T
31. NTSC uses a type of amplitude modulation for the video signal.
ANS: T
32. A standard video broadcast channel is about 4.5 MHz wide.
ANS: F
33. The audio signal in NTSC video uses FM.
ANS: T
34. Color NTSC receivers use a "color-burst" oscillator to create the color signals.
ANS: F
35. A standard broadcast video signal reaches zero level twice per frame.
ANS: F
36. An analog television receiver uses a type of superheterodyne circuit.
ANS: T
37. The accelerating voltage applied to the CRT in a TV receiver is several thousand volts.
ANS: T
38. Color TVs use a higher accelerating voltage than do monochrome receivers.
ANS: T
39. The CRTs commonly used in TV receivers use electrostatic deflection.
ANS: F
40. The "yoke" is part of the deflection circuit.
ANS: T
41. Color TV receivers do not have a "raster".
ANS: F
42. There is very high voltage at the flyback transformer in a TV receiver.
ANS: T
43. Most of the supply voltages in a TV receiver come from the horizontal output transformer.
ANS: T
44. A typical color CRT contains three electron guns.
ANS: T
45. A typical monochrome CRT contains a "shadow mask".
ANS: F
46. In a color CRT, "purity" means each electron beam hits the correct color phosphor.
ANS: T
47. "Aquadag" is a color phosphor.
ANS: F
48. "Ultor" is a color phosphor.
ANS: F
49. In a CATV system, the main antenna is at the "head end".
ANS: T
50. Like a PSTN central office, the typical CATV system is configured as a star network.
ANS: F
51. Noninterlaced scanning is called "progressive" scanning.
ANS: T
52. HDTV uses the same aspect ratio as standard NTSC.
ANS: F
53. An HDTV signal cannot fit into the bandwidth of a standard broadcast TV channel.
ANS: F
54. Digital encoding and compression play a significant role in HDTV.
ANS: T
55. The FCC has set the phase-out of analog TV broadcasting for the year 2006.
ANS: T
56. Color CRTs emit X rays.
ANS: T
MULTIPLE CHOICE
1. NTSC stands for:a. National Television Systems Commissionb. National Television Systems Committeec. National Television Systems Councild. Nippon Television Systems Commission
ANS: B
2. The NTSC specification was drawn up by the:a. FCC c. EIAb. IRE d. IEEE
ANS: C
3. RGB stands for:a. Red-Green Burst c. Red-Green Bandwidthb. Red-Green Brightness d. Red-Green-Blue
ANS: D
4. The number of scan lines in an NTSC signal is:a. 525 c. 1024b. 625 d. 1250
ANS: A
5. The number of NTSC frames sent per second is:a. 25 c. 50b. 30 d. 60
ANS: B
6. The number of NTSC fields sent per second is:a. 25 c. 50b. 30 d. 60
ANS: D
7. The aspect ratio of a standard TV receiver is:a. 3 : 4 c. 525 : 625b. 4 : 3 d. 625 : 525
ANS: B
8. Luminance refers to:a. brightness c. chromab. contrast d. raster
ANS: A
9. Luminance is measured in:a. foot-candles c. IRE unitsb. lumins d. NTSC units
ANS: C
10. The maximum luminance level is called:a. max white c. all whiteb. peak white d. whiter than white
ANS: B
11. The blanking level corresponds to a luminance of:a. white c. whiter than whiteb. black d. blacker than black
ANS: B
12. The sync pulse level corresponds to a luminance of:a. white c. whiter than whiteb. black d. blacker than black
ANS: D
13. The vertical blanking pulse is serrated to:a. maintain horizontal sync c. equalize the DC levelb. maintain vertical sync d. all of the above
ANS: A
14. When measured in lines, horizontal resolution:a. is greater than vertical resolutionb. is about the same as vertical resolutionc. is less than vertical resolutiond. horizontal resolution is not measured in lines
ANS: B
15. The smallest picture element is called a:a. dot c. pixelb. pic d. none of the above
ANS: C
16. In a color TV receiver, Y I Q refers to:a. luminance signal, in-phase color component, quadrature phase color componentb. composite color signal, in-phase color component, quadrature phase color
componentc. composite video signal, in-phase video component, quadrature video color
component
d. a method of demodulating stereo sound
ANS: A
17. Compared to the luminance signal, the horizontal resolution for color is:a. much greater c. much lessb. about the same d. resolution does not apply to color
ANS: C
18. The modulation used for the video signal in a standard NTSC color TV receiver is:a. SSB c. suppressed-carrier AMb. vestigial sideband AM d. FM
ANS: B
19. The modulation used for the audio signal in a standard NTSC color TV receiver is:a. SSB c. suppressed-carrier AMb. vestigial sideband AM d. FM
ANS: D
20. The modulation used for the chroma signal in a standard NTSC color TV receiver is:a. SSB c. suppressed-carrier AMb. vestigial sideband AM d. FM
ANS: C
21. The function of the "color burst" is to:a. detect the presence of a color video signalb. regenerate the color sub-carrierc. to synchronize the color demodulation line by lined. all of the above
ANS: D
22. SAP stands for:a. separate audio program c. sync amplitude pulseb. separate audio pulse d. sync audio pulse
ANS: A
23. The horizontal output transformer is also called:a. the isolation transformer c. the flyback transformerb. the video transformer d. the yoke
ANS: C
24. Compared to a monochrome CRT, the accelerating voltage on a color CRT is:a. about the same c. much lowerb. much higher d. color CRTs use magnetic acceleration
ANS: B
25. Deflection in CRTs used in TV receivers is done:a. magnetically for both vertical and horizontalb. electrostatically for both vertical and horizontalc. electrostatically for vertical and magnetically for horizontald. magnetically for vertical and electrostatically for horizontal
ANS: A
26. AFPC stands for:a. allowed full picture chroma c. automatic frequency and picture
controlb. automatic frequency and phase control d. none of the above
ANS: B
COMPLETION
1. ____________________ is a conductive coating on both the inside and outside of the CRT in a TV.
ANS: Aquadag
2. The ____________________ standard for TV has been in use since 1953.
ANS: NTSC
3. Video systems form pictures by a ____________________ process.
ANS: scanning
4. During the horizontal blanking interval, the electron beam ____________________ from right to left.
ANS: retraces
5. The NTSC specifies a ____________________ video signal.
ANS: composite
6. The ____________________ ratio of a CRT screen is the ratio of width to height.
ANS: aspect
7. Brightness information is called ____________________.
ANS: lumaluminance
8. Color information is called ____________________.
ANS: chromachrominance
9. The blanking period before the sync pulse is called the front ____________________.
ANS: porch
10. Odd and even fields are identified by the ____________________ of the vertical sync pulse.
ANS: position
11. Each horizontal scan line takes ____________________ microseconds, not including blanking.
ANS: 62.5
12. Horizontal blanking lasts ____________________ microseconds.
ANS: 10
13. Vertical blanking lasts about ____________________ milliseconds.
ANS: 1.3
14. Picture elements are called ____________________.
ANS: pixels
15. The maximum number of scan lines under NTSC is ____________________.
ANS: 525
16. The human eye is most sensitive to the color ____________________.
ANS: green
17. The color sub-carrier frequency is approximately ____________________ MHz.
ANS: 3.58
18. SAP stands for ____________________ audio program.
ANS: separate
19. The second anode of a CRT is often called the ____________________.
ANS: ultor
20. The accelerating voltage for a color CRT is about ____________________ kV.
ANS: 20 to 30
21. The inside of a CRT's face-plate is coated with ____________________ to generate the picture.
ANS: phosphor
22. The horizontal output transformer is called the ____________________ transformer.
ANS: flyback
23. A good way to separate luma from chroma is to use a ____________________ filter.
ANS: comb
24. The color ____________________ turns off the color circuitry when a color TV is receiving a monochrome signal.
ANS: killer
25. Signal levels in cable TV systems are usually measured in ____________________.
ANS: dBmV
26. The antenna for a CATV system is located at the ____________________ end.
ANS: head
27. A ____________________ shows a color-bar signal with predetermined levels and phases.
ANS: vectorscope
28. Color intensity is called ____________________.
ANS: saturation
29. The ____________________ of the chroma signal represents the color hue.
ANS: phase
30. The ____________________ controls in a color TV adjust the electron beams to strike the correct color phosphor dots.
ANS: purity
31. The ____________________ controls in a color TV adjust the electron beams to strike the correct triad of phosphor dots.
ANS: convergence
THYRISTORS…
CHAPTER 11 THYRISTORS
CHAPTER 11 THYRISTORS
1. It is like the four-layer diode but with the added gate connection SCR
2. This is the maximum continuous anode current that the device can withstand in the conduction
state under specifies conditions. Average forward current
3. What bilateral thyristor functions basically like two parallel SCRs turned in opposite directions with a common gate terminal? Triac
4. ____________ does not belong to the thyristor family because it does not have a four-layer type of construction. UJT
5. It can be used a trigger device for SCRs and triacs. UJT
6. It is a type of three-terminal thyristor that is triggered into conduction when the voltage at the anode exceeds the voltage at the gate. PUT
7. A region of forward bias in which the device has a very high forward resistance and is in the off state Forward-blocking region
8. A method for turning-off the SCR that basically requires momentarily forcing current through the SCR in the direction opposite to the forward conduction Forced commutation
9. The value of gate current necessary to switch the SCR from the forward-blocking region to the forward-conduction region under specified conditions. Gate Trigger Current
10. A four-layer semiconductor device that operates essentially as does the conventional SCR except that it can also be light-triggered. LASCR
11. Functions basically like two parallel 4- layer diodes turned in opposite directions. Diac
12. A diac with gate terminal Triac
13. A four-terminal thyristor that has two gate terminals that are used t trigger the device on and off Silicon Controlled Device (SCS)
14. A type of three-terminal thyristor that is triggered into conduction when the voltage at the anode exceeds the voltage at the gate.
Programmable Unijunction Transistor (PUT)
15. The characteristic of a UJT that determines its turn-on point Standoff-ratio
16. The four-layer diode is also called Shockley diode
17. The region that corresponds to the on condition of the SCR where there is forward current from anode to cathode through the very low resistance of the SCR Forward_ conduction region
18. The SCR can only be turned on using its _________ terminal Gate
19. Acts as the trigger source in the LASCRs Light
20. A thyristor that conducts when the voltage across its terminals exceeds the breakover potential 4-layer diode
21. Basic methods of for turning off an SCR Anode current interruption and forced commutation
TOMASI…
SATELLITE MULTIPLE ACCESSING ARRANGEMENTS (c26)
CHAPTER 26SATELLITE MULTIPLE ACCESSING ARRANGEMENTS
1)Also called as Multiple Destination, It implies that more than one user has access to one or more radio channels within a satellite communications channel. Multiple AccessingMultiple Accessing Arrangement: Frequency-division multiple accessing (FDMA) Time-division multiple accessing (TDMA) Code-division multiple accessing (CDMA)
2)A given number of the available voice-band channels from each earth station are assigned a dedicated destination.Pre-assignment(dedicated) 3)Voice channels are assigned on an as-needed basis.Demand Assignment 4)The method of assigning adjacent channels different electromagnetic polarizations and is possible by using orthogonal polarization and spacing adjacent channels 20 MHz apart.Frequency Reuse 5)Eskimo word meaning “little brother”.Anik 6)Domestic Satellites operated by Telsat Canada.Anik-E communications Satellite 7)A method of multiple accessing where a given RF bandwidth is divided into smaller frequency bands.FDMA 8)Multiple channel per carrier formats assigned and remain fixed for a long Period of time.Fixed-Assignment, Multiple Access (FAMA)
9)Assigning carrier frequency on temporary basis using a statistical assignment process.Demand-AssignmentMultiple Access 10)An acronym for Single-channel-per-carrier PCM multiple Access Demand-assignment Equipment.SPADE 11)Stands for Single-Carrier-Per-Channel.SCPC 12)A time division-multiplexed transmission that is frequency division multiplexed.Common Signaling Channel (CSC) 13)The predominant Multiple-access method of time-division multiplexing digitally modulated carriers between participating earth stations within a satellite network through a common satellite transponder.TDMA
14)An RF-to-RF repeater that simply receives the earth station transmissions, amplifies them, and then re-transmit them in a downlink beam that is received by all other participating station.Transponder 15)It is where transmissions from all earth stations are synchronized.Reference Burst 16)It is where all receiving stations recover a frequency and phase coherent carrier for PSK demodulationCarrier Recovery Sequence (CRS) 17)An acronym for Conference of European Postal and Telecommunications Administrations, is commonly used TDMA frame format for digital satellite systemCEPT 18)Sometimes referred to as Spread-Spectrum Multipleentire allocated bandwidth Access, the transmissions can spread throughout theCode-Division Multiple Access (CDMA)
19)A unique binary word that each earth station’s transmissions are encoded.Chip Code 20)It compare two signals and recover the original data.Correlator 21)It assigns an individual terrestrial channel (TC) to a particular satellite channel (SC) for the duration of the call.Digital non interpolated Interface 22)It assigns a terrestrial channel to a satellite channel only when speech energy is present on the TC.Digital Speech Interpolated Interface 23)A form of analog channel compression that has been used for sub oceanic cables for many years.Time-Assignment Speech Interpolation (TASI) 24)The art or science of plotting, ascertaining or directing the course of movements, in other words, knowing where you are and being able to find your way around.Navigation 25)It is the most ancient and rudimentary method of navigation and simply continuing to travel about until you reach your destination, assuming of course that you have one.Wandering
26)Earliest effective means of navigation wherein direction and distance are determined from precisely timed sightings of celestial bodies, including the stars and moon.Celestial Navigation 27)Method of navigation by means of fixing a position and direction with respect to familiar, significant landmarks such as railroad tracks, water towers, barns, mountains and bodies of water.Piloting
28)A navigation technique that determines position by extrapolating a series of measured velocity increments.Dead Reckoning 29)The term derived from the word “deduced” and not necessarily from the fate of the people who used the technique.Dead 30)He used dead reckoning successfully in 1927 during his historic 33-hour transatlantic journey.Charles Lindbergh 31)She attempted to make the first around-the-world in 1937 using the dead reckoning technique.Amelia Earhart 32)Navigation technique wherein the position is deter-mined by measuring the travel time of an electro magnetic wave as it moves from a transmitter to a receiver.Radio Navigation 33)A radio Navigation system for terrestrial surface broadcast.Decca 34)Radio Navigation system that provide global coverage and terrestrial surface broadcast.Omega 35)Also a terrestrial surface broadcast.LORAN 36)Low-orbit satellite broadcast, provides global coverage.Navy Transit GPS 37)Medium-orbit satellite broadcast also provides global coverage.Navstar GPS
38)Means of radio navigation in which receivers acquire Coded signals from two pairs of high-powered, land based transmitters whose locations are precisely known.LORAN 39)An acronym for Navigation System with Time and Ranging.Navstar
40)An abbreviation for Global Positioning System.GPS Two levels of service or accuracy: Standard Positioning Service Precise Positioning Service
41)A satellite-based open navigation system which simply means that it is available to anyone equipped with a GPS receiver. Navstar GPSConsists of three segments: a space segment a ground control segment user segment
42)It is when was the Navstar declared as fully operational by the U.S. Air Force Space Command.April 27, 1995 43)It was completed in 1994 and is maintained by the United States Air Force.Navstar Satellite System 44)A positioning and timing service that is available to all GPS users on a continuous, worldwide basis with no direct change.Standard Positioning Service 45)Sometimes called Space Segment, consists of 24operational satellites revolving around Earth in six orbital planes approximately 60° apart with four satellites in each plane.Satellite Segment 46)It produces highly accurate timing signals for satellites.Cesium Atomic Clock 47)A unique integer number that is used to encrypt the signal from that satellite.Pseudorandom Noise (PRN) Code Number 48) A term associated with a table showing the position of a heavenly body on a number dates in a regular sequence, in essence, an astronomical almanac.Ephemeris
49)Error in the receiver’s clock which affects the accuracy of the time-difference measurement.Clock Bias Error 50)The Navstar control segment.It consists of : Fixed-location ground based monitor stations Master Control Station uplink transmitterOperational Control System 51)It makes standard GPS more accurate. It works by canceling out most of the natural and man-made errors that creep into normal GPS measurements.Differential GPS0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Satellite, Tomasi
SATELLITE COMMUNICATIONS (c25 Tomasi)
CHAPTER 25SATELLITE COMMUNICATIONS
1)A celestial body that orbits around a planet.Satellite2)Man-made satellites that orbit earth, providing a multitude of communication functions to a wide variety of consumers, including military, governmental, private and commercial subscriber.Communications Satellites3)A satellite radio repeater which a satellite may have many.Transponder Consists of :input Bandlimiting device (BPF)input low-noise amplifier (LNA)frequency translatorlow level amplifieroutput bandpass filter
4)It consists of one or more satellite space vehicles, a ground-based station to control the operation of the system, and a user network of earth stations that provides the interface facilities for the transmission and reception of terrestrial communications traffic through the satellite system.Satellite System
5)It includes control mechanism that support the payload operation.Bus6)The actual user information conveyed through the system.Payload
7)A type of satellite wherein it simply “bounces” signals from one place to another.Passive Reflector8)A natural satellite of Earth, visible by reflection of sunlight having a slightly elliptical orbit.Moon9)Used by passive satellites for tracking and ranging purposes.Radio Beacon Transmitters10)Launched by Russia, the first active earth satellite in 1957. It transmitted telemetry for 21 days.Sputnik I11)A type of satellite capable of receiving, amplifying, reshaping, regenerating and retransmitting information.Active Satellite12)Satellite launched by U.S., it transmitted telemetry information for nearly five months.Explorer I13)Satellite launched by NASA in 1958, a 150-pound conical-shaped satellite. It was the first artificial satellite used for relaying terrestrial communications.Score14)The first active satellite to simultaneously receive and transmit radio signals.Telstar I15)Launched in 1963, and was used for telephone television, facsimile and data transmission and accomplished the first successful transatlantic video transmission.Telstar II16)Launched in February 1963, was the first attempt to place a geosynchronous satellite into orbit.Syncom I
17)It was the first commercial telecommunications satellite. It launched from Cape Kennedy in 1965 and used two transponders. Also called as Early Birds.It stands for International Telecommunications Sate-llite.Intelsat I18)Domestic satellite launched by former Soviet Union in 1966. It means “lighting”.Molya19)A German astronomer who discovered the laws thatgoverns satellite motion.Johannes Kepler20)It may be simply stated as: The planets move in ellipses with the sun at one focus The line joining the sun and the planet sweeps out equal intervals of time.The square of the time of revolution of a planet divided by the cube of its mean distance from the sun gives a number that is the same for all planets.Kepler’s Law
21)The point in an orbit closest to earthPerigee22)The point in an orbit farthest from the earth.Apogee23)It states that the square of the periodic time of orbit is proportional to the cube of the mean distance between the primary and the satellite.Harmonic Law24)High-altitude earth-orbit satellites operating primarily in the 2-GHz to 18 GHz frequency spectrum with orbits Satellite 22,300 miles above earth’s surface.Geosynchronous SatelliteAdvantages of Geosynchronous Satellite:It remain almost stationary in respect to a given earth station.Available to earth within their shadows 100% of the time.No need to switch from one geosynchronous satellite to another as they orbit overheadThe effects of Doppler shift are negligibleDisadvantages of geosynchronous Satellite:It requires sophisticated and heavy propulsion device onboard to keep them in a fixed orbitMuch longer propagation delaysRequires higher transmit power and more sensitive receivers because of the longer distances and greater path loss.High precision spacemanship is required.25)The angle between the earth’s equatorial plane and the orbital plane of a satellite measured counter clockwise at the point in the orbit where it crosses the equatorial plane traveling from south to north called the ascending node.Angle of Inclination26)The point where the polar or inclines orbit crosses the equatorial plane travelling from north to southDescending Node27)The line joining the ascending and descending nodeLine of Nodes28)It is when the satellite rotates in an orbit directl above the equator, usually in a circular path.Equatorial Orbit
29)It is when the satellite rotates in path that takes over the North and the South poles in an orbit that is close to earth and passes over and very close to both the North and South Poles.Polar Orbit30)The noise power normalized to a 1 Hz bandwidth, or the noise power present in a 1Hz bandwidthNoise Density31)It identifies the system parameters and is used to determine the projected carrier-to-noise ratio and energy Bit-to-noise density ratio at both the satellite and earth station receivers for a given modulation scheme.Link Budget
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MICROWAVE RADIO COMMUNICATIONS AND SYSTEM GAIN (c22 Tomasi)
CHAPTER 24MICROWAVE RADIO COMMUNICATIONS AND SYSTEM GAIN
1)Electromagnetic waves with frequencies that range from approximately 500 MHz to 300 GHz or more.Microwaves2)The wavelengths for microwave frequencies, which is than infrared energy.1 cm and 60 cm slightly longer3)The name given to microwave signals, because of their inherently high frequencies, have short wavelengths.“Microwave” waves4)Each frequency is divided in half with the lower half identified as the low band and the upper half as narrow band.Full-Duplex (Two-way)5)Communications system used to carry information for relatively short distances such as between cities with the same state.Short Haul6)Microwave systems that is used to carry information for relatively long distances, such as interstate and backbone route applications.Long Haul7)It propagate signals through Earth’s atmosphere between transmitters and receivers often located on top of tower spaced about 15 miles to 30 miles apart.Microwave Radios Advantages of Microwave Radio: Radio systems do not require a right-of way acquisition between stations. Each station requires the purchase or lease ofonly a small area of land. Because of their high operating frequencies, microwave radio systems can carry large quantities of information. High frequencies mean short wavelengths, which require relatively small antennas. Radio signals are more easily propagated around physical obstacles such as water and high mountains Fewer repeaters are necessary for amplification. Distances between switching centers are less. Underground facilities are minimized. Minimum delays are introduced. Minimal crosstalk exists between voice channels. Increased reliability and less maintenance are important factors.
Disadvantages of Microwave Radio: It is more difficult to analyze and design circuits at microwave frequencies. Measuring techniques are more difficult to perfect and implement at microwave frequencies. It is difficult to implement conventional circuit components at microwave frequencies. Transient time is more critical at microwave frequencies. It is often necessary to use specialized components for microwave frequencies. Microwave frequencies propagate in a straight line, which limits their use to line-of-sight applications.8)Propagates signals outside the Earth’s atmosphere and are capable of carrying signals much farther while utilizing fewer transmitters and receivers.Satellite Systems9)It is used in microwave radio systems rather than amplitude modulation because AM signals are more sensitive to amplitude nonlinearities inherent in wide-band microwave amplifiers.Frequency Modulation
10)Major factor when designing FM Radio systems. It is caused by repeater amplitude nonlinearity in AM, while in FM, it is caused by transmission gain and delay distortion.Intermodulation Noise11)The composite signal that modulates the FM carrier and may comprise one or more of the following: Frequency-division multiplexed voice-band channels Time-division-multiplexed voice-band channels Broadcast-quality composite video or picture phone Wideband dataBaseband12)It provides an artificial boost in amplitude to the higher baseband frequencies.Preemphasis Network13)Frequency modulation index used in the FM deviator. Typically, modulation indices are kept between 0.5 and 1.Low-Index
14)FM signal that is produces at the output of the deviator with a low-index frequency modulation.Narrowband FM15)A receiver and a transmitter placed back to back or in tandem with the system.Microwave Repeaters16)It receives a signal, amplifies and reshapes it, and then retransmit the signal to the next repeater or terminal station down line from it.Repeater StationTypes of Microwave repeaters: IF Baseband RF
17)The received RF carrier is down-converted to an IF frequency, amplified, reshaped, up-converted to an RF frequency, and then retransmitted.IF Repeater18)Generally less than 9 MHz.Baseband Frequencies19)The range id 60 MHz to 80MHz.IF frequencies20)Another name for a Local oscillator, is considerably lower in frequency than either the received or the transmitted radio frequencies.Shift Oscillator21)Transmission used by microwave systems wherein a direct signal path must exist between the transmit receive antennas.Line-of Site Transmission22)A temporary reduction in signal strength which last in milliseconds for several hours or even days.Radio Fade23)It suggests that there is more than one transmission path or method of transmission available a transmitter and a receiver.Diversity24)It is simply modulating two different RF carrier frequencies with the same IF intelligence, then transmitting both RF signals to a given destination.Frequency Diversity25)The output of a transmitter is fed to two or more antennas that are physically separated by an appreciable number of wavelengths.Space Diversity26)A single RF carrier is propagated with two different electromagnetic polarizations. It is generally used in conjunction with space diversity.Polarization Diversity
27)It is more than one receiver for a single radio-frequency channel. With frequency diversity, it is necessary to also use receiver diversity because each transmitted frequency requires its own receiverReceiver Diversity28)Another form of Hybrid diversity and undoubtly provides the most reliable transmission but most expensive. It combines frequency, space, polarization and receiver diversity into one system.Quad Diversity29)A specialized form of diversity that consist of a standard frequency diversity path where the two transmitter/ receiver pairs at one end of the path are separated from each other and connected to different antennas that are vertically separated as in space diversity.Hybrid Diversity29)Alternate facilities temporarily made to avoid a service interruption during periods of deep fades or equipment failures.Protection Switching Arrangement
types of protection switching arrangements: hotstandby diversity
30)Each working radio channel has a dedicated backup or spare channel.Hot Standby Protection31)A single backup channel is made available to as many as 11 working channels.Diversity Protection32)In hotstandby protection, it splits the signal power and directs it to the working and the spare (standby)microwave channels simultaneously.Head-End Bridge33)It has two working channels, one spare channel, and an auxiliary channel.Diversity Protection
34)A low-capacity low-power microwave radio that is designed to be used for a maintenance channel only.Auxilliary Channel35)It is where the number of repeater stations between protection switches depends.Reliability Objectives of the Systems36)Points in the system where baseband signals either originate or terminate. Terminal Stationsfour major sections: baseband wireline entrance link (WLEL) FM-IF RF sections
37)Points in a system where baseband signals may be reconfigured or where RF carriers are simply “repeated” or amplified.Repeater Stations38)Stands for WireLine Entrance Link, it serves as the interface between the multiplex terminal equipment and the FM_IF equipment.WLEL
39)A balanced modulator that, when used in conjunction with a microwave generator, power amplifier, and band-pass filter, up-converts the IF carrier to an RF carrier and amplifies the RF to the desired output power.Transmod
40)It must be capable of amplifying very high frequencies and passing very wide bandwidth signals for microwave radios.Power Amplifiers devices used in microwave amplifiers: Klystron Tubes Traveling-wave tubes (TWTs) IMPATT (Impact avalanche and transit time)
41)It provides the RF carrier input to the up-converter. It is called as microwave generator rather than an oscillator because it is difficult to construct a stable circuit that will oscillate in the gigahertz range.Microwave Generator42)It operates in the range 5 MHz to 25 MHz, used to provide a base frequency that is multiplied up to the desired RF carrier frequency.Crystal-controlled Oscillator43)A unidirectional device often made from ferrite material. It used in conjunction with a channel-combining network to prevent the output of one transmitter from interfering with the output of another transmitter.Isolator44)Stands for Automatic Gain Control, is a circuit in an IF amplifier.AGC45)It occurs only when three stations are placed in a geographical straight line in the system.Multi-hop Interference46)It prevents the power that “leaks” out the back and sides of a transmit antenna from interfering with the signal entering the input of a nearby receive antenna.High/Low-Frequency Scheme47)The signal entering the input of a nearby receive antenna.Ring around48)It means that this channels are propagated with vertical polarization.V Channels49)The line-of-sight directly between the transmit and receive antenna. Also called as the Direct Wave.Free-Space Path50)It consists of the electric and magnetic fields associated with the currents induced in earth’s surface.Surface Wave
51)The portion of the transmit signal that is reflected off Earth’s surface and captured by the receive antenna.Ground-Reflected Wave52)The portion of the transmit signal that is returned back to Earth’s surface by the ionized layers of earth’s atmosphere.Sky Wave53)The loss incurred by an electromagnetic wave as it propagates in a straight line through a vacuum with no absorption or reflection of energy from nearby objects.Free-Space Path Loss54)A phenomenon wherein electromagnetic energy is spread out as it propagates away from the source resulting in lower relative power densities.Spreading Loss55)The reduction in signal strength at the input to a receiver.Fading
56)The difference between the nominal output power of a transmitter and the minimum input power to a receiver necessary to achieve satisfactory performance.System Gain57)Sometimes called as Link Margin, is essentially a “fudge Factor” included in system gain equations that considers the non ideal and less predictable characteristics of radio wave propagation and terrain sensitivity.Fade Margin58)He described ways of calculating outage time due to fading on a non diversity path as a function of terrain, climate, path length, and fade margin, in April 1969.W.T. Barnett59)From Bell Laboratories, he derived formulas for calculating the effective improvement achievable by vertical space diversity as a function of the spacing distance, path length, and frequency in June 1970.Arvids Vignant60)The ratio of the wideband “carrier” to the wideband noise power.Carrier-to-Noise Ratio (C/N)61)Also called Receiver Sensitivity, is the minimum wide band carrier power at the input to a receiver that willprovide a usable baseband output.Receiver Threshold62)The carrier-to-noise ratio before the FM demodulator.Pre-detection Signal to-Noise Ratio63)The carrier-to-noise ratio after the FM demodulator.Postdetection Signal-to-Noise Ratio64)A ratio of input signal-to-noise ratio to output signal to noise ratio.Noise Factor (F)65)The noise factor stated in dB and is a parameter commonly used to indicate the quality of a receiver.Noise Figure0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Microwave, Tomasi
Tuesday, September 6, 2011
DATA-LINK PROTOCOLS AND DATA COMMUNICATIONS NETWORKS (c23 Tomasi)
CHAPTER 23DATA-LINK PROTOCOLS AND DATA COMMUNICATIONS NETWORKS
1)The primary goal of __________ is to give users of a network the tools necessary for setting up the network and performing data flow control.
Network Architecture
2)A set of rules implementing and governing an orderly exchange of data between two layer devices.Data-Link Protocol
3)The transmitting station in a data link protocol.Master Station
4)The receiving station in a data link protocol.Slave Station
5)Data link network wherein all stations have equal access to the network.Peer-to Peer Network
6)Discipline, Flow Control and Error Control.Functions of Data-link Protocol
7)Coordinates hop-to-hop data delivery where a hop may be a computer, a network controller, or some type of network-connecting deviceLine Discipline
8)Determines which device is transmitting and which is receiving at any point in time.Line Discipline
9)Coordinates the rate which data are transported over a link and generally provides an acknowledgement mechanism.Flow Control
10)Specifies means of detecting and correcting transmission errors.Error Control
11)Two fundamental ways that line discipline is accomplished in a data communications network.Enquiry/Acknowledgement(ENQ/ACK) and Poll/Select
12)It determines which device on the network can initiate a transmission and whether the intended receiver is available and ready to receive a message.ENQ/ACK
13)The initiating station begins a session by transmitting a frame, block, or packet of data called _________, which identifies the receiving station.Enquiry(ENQ)14)The response of the destination station when it is ready to receive.Positive Acknowledgement (ACK)
15)The response of the destination station when it is not ready to receive.Negative Acknowledgement (NAK)
16)The best application of the poll/select line discipline.Centrally Controlled Data Network
17)A solicitation sent from the primary to a secondary to determine if thesecondary has data to transmitPoll
21)A set of procedures that tells the transmitting station how much data it can send before it must stop transmitting and wait for an acknowledgment from the destination stationFlow Control
22)The transmitting station sends one message frame and then waits for an acknowledgement before sending the next message frame.Stop-and Wait Flow Control
23)A source station can transmit several frames in succession before receiving an acknowledgement.Sliding Window Flow Control
24)It refers to imaginary receptacles at the source and destination stations with the capacity of holding several frames of data.Sliding Window
25)Primary advantage of sliding window control.Network Utilization
26)Primary disadvantages of sliding window flow control.Complexity and Hardware Capacity
27)Interpret a frame of data as a group of successive bits combined into predefined patterns of fixed length, usually eight bits each.Character Oriented Protocols
28)Another name for character oriented protocols.Byte-oriented Protocols
29)A discipline for serial by bit information transfer over a data communications channel.Bit Oriented Protocol
30)A character-oriented protocols generally used on two point networks using asynchronous data and asynchronous modems.Asynchronous Data link Protocols
31)Developed the first file transfer protocol designed to facilitate transferring data between two personal computers in 1979.Ward Christiansen
32)Cristiansen's protocol which is relatively simple data link protocol intended for low-speed applications.XMODEM
33)Remote stations can have more than one PC or printer.Synchronous Data-Link Protocols
34)A group of computers, printers, and other digital devices.Cluster
35)A synchronous character-oriented data link protocol developed by IBM.Binary Synchronous Communications (BSC)
36)Another name for BSC.Bisync
37)Another name for enquiry (ENQ) character.Format or line turn around
38)The __________ uses longitudinal redundancy checking (LRC) with ASCII-coded messages and cyclic redundancy checking.Block Check Character (BCC)
39)A synchronous bit oriented protocol developed in the 1970's by IBM for use in system network architecture environment.Synchronous Data-Link Control (SDLC)
40)Three transmission states.Transient, Idle and Active
41)Flag Fields, Address Field, Control Field, Information and Frame Check Sequence Field are __________.SDLC Frame Fields
42)It is used for the delimiting sequence for the frame and to achieve frame and character synchronization.Flags
43)It is used for polling, confirming previously received frames, and several other data link management functionsControl Field
44)Three frame formats with SDLC.Information, Supervisory and Unnumbered
45)A command or a response that is used to send unnumbered information.Unnumbered Information (UI)
46)A command that places a secondary station into the initialization mode.Set Initialization Mode
47)A response sent by a secondary station to request the primary to send a SIM command.Request Initialization Mode (RIM)
48)A command that places a secondary into the normal response mode.Set Normal Response Mode (SNRM)
49)A response transmitted from a secondary station if the primary attempts to send numbered information frames to it when the secondary is in the normal disconnect mode.Disconnect Mode (DM)
50)A response sent by a secondary when it wants the primary to place it in the disconnect mode.Request Disconnect (RD)
52)An affirmative response that indicates compliance to SIM, SNRM or DISC commandsUnnumbered Acknowledgement
53)An exchange of frames between the primary station and a secondary station.TEST
54)A flag followed by eight consecutive logic 0's.Turnaround Sequence
55)A SDLC subcommand causes all previously set functions to be cleared by the secondary.Clear
56)A SLDC subcommand causes the secondary receiving it to turn on or turn off its carrier.
Beacon Test
57)A SDLC command causes the addressed secondary station to pace itself into the monitor mode.Monitor Mode
58)A SDLC command causes a secondary station to loop its transmission directly to its receiver input.Wrap
59)A SDLC command causes the addressed secondary to initiate a series of internal diagnostic tests.Self-Test
60)The transparency mechanism used with SDLC.Zero Bit Insertion or Zero Stuffing
61)It is used prematurely terminate an SDLC frame.Message Abort
62)The encoding scheme used in SDLC.Invert-On-Zero Coding
63)Standard that defines the frame structure, delimiting sequence, transparency mechanism and error detection method used with HDLC.ISO 3309
64)Operational Mode of SDLC.Normal Response Mode (NRM)
65)A mode of operation logically equivalent to a two point private line circuit where each station has equal data link responsibilities.Asynchronous Balanced Mode
66)A switched data communications network similar to the public telephone network except a PDN is designed for transferring data only.Public Switched Data Network (PDN)
67)It is used when making a standard telephone call on the public telephone network.Circuit Switching
68)Is a form of store and forward network.Message Switching
69)Another name for packet switching.
Hold and Forward Network
70)A user interface as the international standard for packet network access.X.25
71)SA logically equivalent to a two point dedicated private line circuit except slower.Permanent Virtual Circuit (PVC)
72)A logically equivalent to making a telephone call through the DDD network except no direct end to end connection is made.Virtual Call
73)Identifies whether the packet is a new call request or a previously established call.Format Identifier
74)A 12 bit binary number that identifies the source and destination users for a given virtual call.Logical Channel Identifier
75)This four bit gives the number of digits that appear in the calling address filed.Calling Address Field
76)This field is the same as the calling address field except that it identifies the number of digits that appear in the called address fieldCalled Address Length
77)This field contains the destination address.Called Address
78)This field is the same as the called address field except that it contains up to 15 BCD.Calling Address
79)This field identifies the number of eight bit octets present in the facilities field.Facilities Length Field
80)This 32 bit field is reserved for the subscriber to insert user level protocol.Protocol Identifier
81)A proposed network designed by the major telephone companies in conjunction with the ITU-T.Integrated Services Digital Network (ISDN)
82)Customers gain access to the ISDN system through a local interface connected to a digital transmission medium.Digital Pipe
83)ISDN objectives that ensure universal access to the network.System Standardization
84)Said objectives that allow customers to use a variety of protocols and applicationsAchieving Transparency
85)ISDN should not provide services that preclude competitivenessSeparating Functions
86)Provide private-line and switched services refers what objectives of ISDN.Variety of Configurations
87)ISDN services should not be directly related to cost and independent of the nature of the data.Addressing Cost-Related Tariffs
88)Provide a smooth transition while evolving.Migration
89)Provide service to low capacity personal subscribers as well as to large companies.Multiplexed Support
90)Translation between non-ISDN data protocol and ISDN is performed in this device.Terminal Adapter
91)A boundary to the network and may be controlled by the ISDN provider.Network Termination 1
92)Refers to interfaces between the common carrier subscriber loop and the central office switchU-Reference Point
93)The media interface point between an NT1 and the central office.U Loop
94)It is defined by ITU-T as a service that provides transmission channels capable of supporting transmission rates greater than the primary data rate.Broadband ISDN
95)Information transfer is primarily from service provider to subscriberDistribution Services
96)Codes the data information into smaller packets used by the BISDN networkBroadband Node
97)A connection between a source and a destination, which may entail several ATM links.Virtual Channel
98)Once data have entered the ATM network, they transferred into fixed time slots called ________.Cells
99)Controls the flow of traffic across the user network interface (UNI) and into the network.Generic Flow Control Field (GFC)
100)The first three bits of the second half of byte 4 specify the type of message in cell.Payload Type Identifier
101)Information fields that are designed to accommodate PCM-TDM traffic, which allows the ATM network to emulate voice or DSN services.Constant Bit Rate
102)A portion of a public service provider's switching system where the service provider could be a local telephone company or a long-distance carrier.Public ATM Switches
103)Provides the most effective and economical means of handling local data communications field.Local Area Networks (LAN)
104)A communications system that allows users to send messages to each other through their computers.E-Mails
105)LAN Topologies.Star, Bus and Ring Topology
106)It describes how users access the communications channel in a LAN.Network Access Methodologies
107)Access method used primarily in bus topology.CDMA/CD
108)It two stations transmit at the same time, ________ occurs.Collision
109)The time it takes a signal to travel from a source to a destination.Propagation Delay
110)A base band transmission system designed in 1972 by Robert Metcalfe and David Boggs.Ethernet
111)Its purpose is to establish clock synchronization.Preamble
112)It is simply a series of two logic 1's appended to the end of the preamble.Start Frame Delimiter
113)Consists of six bytes the corresponds to the address of the station sending the frame.Source Address
TRANSISTOR…
CHAPTER 8 FIELD –EFFECT TRANSISTORS
CHAPTER 8 FIELD –EFFECT TRANSISTORS
1. FETs are preferred device in low-voltage switching applications; while______ transistor is generally used in high-voltage switching applications. IGBT
2. What type of JFET operates with a reverse-biased pn junction to control current in the channel? JFET
3. An n-channel universal transfer characteristic curve is also known as Transconductance curve
4. The change in drain current for a given change in gate-to-source voltage with the drain-to-source voltage constant
Forward transconductance
5. What is the most common type of JFET bias? Self-bias 6. It is a method for increasing the Q-point stability of a self-biased JFET by making the drain current essentially independent of gate-to-source voltage Current-source bias
7. What JFET bias uses a BJT as a constant-current source? Current-source bias
8. For increased Q-point stability, the value of RS in the self-bias circuit is increased and connected to a negative supply voltage. This sometimes called Dual-supply bias
9. VGS varies quite a bit for JFET self-bias and voltage-divider bias but ID is much more stable with Voltage-divider bias
10. ____________ is sometimes called depletion/enhancement MOSFET. D-MOSFET
11. LDMOSFET has a lateral channel structure and is a type of Enhancement MOSFET
12. It is an example of the conventional E-MOSFET designed to achieve higher power capability
VMOSFET
13. Following are the three ways to bias a MOSFET except Current-source bias
14. The insulated-gate bipolar transistor combines which two transistors that make it useful in high-voltage and high-current switching applications? BJT and MOSFET
15. What are the three terminals of IGBT? Gate, collector, emitter
16. In terms of switching speed, __________ switch fastest and _____________ switch slowest. MOSFETs, BJTs
17. In a MOSFET, the process of removing or depleting the channel of charge carriers and thus decreasing the channel conductivity Depletion
18. The ratio of change in drain current to a change in gate-to source voltage in a FET Transconductance
19. A FET is called a ______________ because of the relationship of the drain current to the square of a term containing gate-to-source voltage Square-law device 20. Combines features from both the MOSFET and the BJT that make it useful in high-voltage and high-current switching applications. IGBT
21. Has a lateral channel structure and is a type of enhancement MOSFET designed for power applications. LDMOSFET 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Transistor CHAPTER 5 TRANSISTOR BIAS CIRCUITS
1. What biasing method is common in switching circuits? Base bias 2. A Base bias in linear region shows that it is Directly dependent on dc beta
3. In an emitter-feedback bias, if the collector current increases, the emitter voltage Increases
4. What happens to the base voltage in no. 10? Increases 5. In an emitter-feedback, the increase in base voltage _________ the base current. Reduces 6. For collector-feedback bias, what provides the bias for the base-emitter junction? Collector voltage 7. As temperature goes up in a collector-feedback circuit, βDC and VBE goes _______ and __________, respectively. Up and down
8. Collector-feedback bias provides good stability using negative feedback from Collector to base
9. Innovations in technology would allow a doubling of the number of
transistors in a given space every year and that the speed of those transistors would increase. This prediction is widely known as Moore’s law
10. If an amplifier is not biased with correct dc voltages on the input and output, it can go ___________ when an input signal is applied. Saturation or cutoff
11. Given a voltage-divider biased BJT, determine IC given VCC, R1, R2, RC, and RE which are 10V, 10kohms, 4.7kohms, 1kohm, and 470ohms respectively. Use βDC= 100. 5.31mA
12. What is the value of VCE in no.20? 2.19 V
13. If an emitter resistor is added to a base bias circuit, what is the value of the emitter current given VCC, RE, RC, and RB as 10V, 1kΩ, 470Ω, and 180kΩ, respectively. Use βDC=100. 3.32mA
14. Calculate for VCE in no. 22 5.12 V
15. If the dc beta in the preceding drops half of its original value, find the percent change in IC. 39.16%
16. What is the percent change in VCE? 27.17%
17. The region along the load line including all points between saturation and cutoff Linear region
18. A voltage divider for which loading effects can be neglected Stiff voltage divider
19. The base bias circuit arrangement has poor stability because its Q-point varies widely with Dc beta
20. The purpose of biasing a circuit is to establish a proper stable ________. Q-point
21. The process of returning a portion of a circuit’s output back to the input
in such a way as to oppose or aid a change in the output Feedback 0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Electronics, Notes, Transistor
Saturday, September 10, 2011
CHAPTER 4 BIPOLAR JUNCTION TRANSISTORS
CHAPTER 4BIPOLAR JUNCTION TRANSISTORS
1. Which is the least of the three transistor currents?Base
2. The ratio of the dc collector current to the dc base current of the transistor is,dc beta/dc current gain
3. the ratio of the dc collector current to the dc emitter currentdc alpha
4. Determine the base current given dc beta=100 , dc alpha=0.85, and IC= 3.70mA0.037mA
5. Nonconducting state of a transistorCutoff
6. State of a BJT in which the collector current has reached maximum and is dependent of the base current Saturation
7. Neither the base-emitter nor the base-collector junctions are forward-biasedcutoff
8. dc beta varies withcollector current and temperature
9. hFE varies with which transistor current/s?Collector only
10. Converts light energy to electrical signalPhototransistor
11. Devices used to electrically isolate circuitsOptocouplers
12. A key parameter in optocouplers is the CTR. CTR stands forCurrent transfer ratio
13. Indication of how efficiently a signal is coupled from input to outputCTR
14. RF transistors are designed to operate atEHF
15. What transistor category/ies uses plastic or metal packages?General-purpose transistors
16. To operate as an amplifier, BE junction must be forward-biased and the BC junction must be reverse-biased. This is calledForward-reverse bias
17. In a phototransistor, what transistor current/s is produced and controlled by light?Base
18. Two basic package typesThrough-hole and surface mount
19. The process of increasing the power, voltage, or current by electronic means.Amplification
TRANSMISSION LINES…
TRANSMISSION FUNDAMENTALS (C1 Past Board :excel:)
CHAPTER 1 TRANSMISSION FUNDAMENTALS (Past Board :excel:)
ECE Board Exam April 2001An SWR reading which has a short circuit termination.Infinity
ECE Board Exam November 2000In an open wire transmission line, what is the normal separation between its two (2) conductors?2 to 6 cm
ECE Board Exam April 2000Which of the following term is used to describe the attenuation and phase shift per unit length of a transmission line?Propagation constant
ECE Board Exam November 1999An indication in radio communication when the voltage standing wave ratio is equal to zero.No input power
ECE Board Exam April 1999Refers to a connector that normally connects RG-213 coaxial. cable to an HF transceiver.PL-259
ECE Board Exam November 1998Width of frequency band just enough to ensure the transmission of information at a required rate and quality required, and under a specified condition and class of emission.Necessary bandwidth
ECE Board Exam. April 1998 Best describe a dip meter.A variable LC oscillator with metered feedback current
ECE Board Exam. April 1997 The standard test tone.0 dBm
ECE Board April 1997If voltage change is equal to twice its original value,. what is it corresponding change In dB?6 dB
ECE Board Exam November 1996Energy that has neither been-radiated into space,nor completely transmitted.Standing waves
ECE Board Exam April 1997To a couple a coaxial line, it is better to use a________Balun
ECE Board Exam November 2000What is the main reason,why coaxial cable is not used in microwe signal transmission?High attenuation
ECE Board Exam April 1997What is impedance of a balance 4-wire with a diameter of 0.25 spaced 2.5 cm apart using an insulator with a dielectric constant of 2.56?100 ohms
ECE Board April 2000In wire communications, non-resonat transmission lines are referred to as __________Flat lines
ECE Board Exam November 1999An electronic equipment used in radio communications to measure standing wave ratio.Reflectometer
ECE Board Exam April 1999How does a shorted half-wave line act at a certain operating frequency?Series resonant circuit
ECE Board Exam November 1998Best choice of transmission line component to couple a coaxial line to a parallel-wire line.Balun
ECE Board Exam April 1998Referred to the dielectric constant of a transmission line material.Velocity factor
ECE Board Exam April 1997What is the characteristic impedance of a single wire with a diameter d=0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart? The wire is held by a material with a velocity factor of 0.75?75 ohms
ECE Board Exam March 1996The power of standard test tone is normally ______1mW
ECE Board Exam November 1996 Which tester is used to measure SWR?Reflectometer
ECE Board Exam March 1996The characteristic impedance of a transmission line does not depend upon its________Length
ECE Board Exam April 2000What is the input impedance equivalent of an open ended transmission line which is longer than a quarter wavelength?As pure inductor
ECE Board Exam November 1999In the study of transmission cable, twin lead. is also referred to as a_________ribbon cable
ECE Board Exam April 1999
The greater the diameter of a wire, the _________ is the resistance.Lesser
ECE Board Exam November 1998What determines the velocity factor in transmission line?Dielectrics in the line
ECE Board Exam April 1998Technical study which deals with production, transport and delivery of a quality signal from source to destinationTransmission System Engineering
ECE Board Exam April 1997If you have available number of power amplifiers with a gain of 100 each how many such amplifiers do you need to cascade to give an overall gain of 60 dB?3 amplifiers
ECE Board Exam March 1996What :is the reference tone level for dBm?-90dBm
ECB Board Exam April 2060What is the term for the ratio of actual velocity at which a signal travels through a line to the speed of light in a vacuum?Velocity factorECE Board Exam November 1999 Referred to as a cause of crosstalk.Electrical coupling between transmission media
ECE Board Exam November 1998What is the meaning of the term velocity factor of a transmission line?The velocity of the wave on the transmission line divided by the velocity of the light in a vacuum
ECE Board Exam April 1998
It is used to connect computers in the same building or in same area.LAN
ECE Board Exam April 1997What do you call the energy that was not radiated into space or completely transmitted?Standing waves
ECE Board Exam November 1996What is the applied power if a thermal RF wattmeter is connected to a transmitter through variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used.2.656 Watts
ECE Board Eaagl.March 1996If the terminating impedance is exactly equal to the characteristic impedance of the transmission line the return loss is ______infinite
ECE Board Exam April 1997A singie.q nductor running from the transmitter to the antenna.Single line wire
ECE Board Exam November 1996Ina transmission line if the maximum current to minimum current ratio is 2:1. what is the ratio of the maximum voltage to minimum voltage?2.1
ECE Board Exam March 1996What is the main purpose of a communications system?To provide an acceptable replica of the information at the destination
ECE Board Exam April 1997__________ sets the limit on the maximum capacity of a channel with a gin noise level. Shannon-Hartley theorem
ECE Board Exam November 1996Which stands for dB relative level?dBr
ECE Board Exam March 1996To connect coaxial line to a parallel-wire, _______ is the best to use
Balun
ECE Board Exam November 1998Which of the following determines the characteristics of a transmission line?Physical dimensions
ECE Board Exam.April 1998Which of the fotlowing is an impedance matching ratio of coax balun?4:1
ECE Board Exam November 1997An electronic equipment used to measure standing wave ratio.Reflectometer
ECE Board Exam April 1997What frequency does oxygen cause excessive attenuation?60 GHz
ECE Board Exam November 1996The standing wave ratio is equal to _________ if the load is properly matched with the transmission line.1
ECE Board Exam March 1996Characteristic impedance of a transmission line is the impedance measured at the ____ when its length is infinite.Input
ECE Board Exam March 1996What.quarterwave transformer will match a 100 ohms line to an antenna whose value is 175 ohms?132.29 ohms
ECE Boardd Exam March 1996When a transmission line uses ground return, it is called a/an __________ line.Unbalanced
ECE Board Exam November 1996
Transmission lines when connected to antenna haveresistive load atthe resonant frequency
ECE Board Exam March 1996Termination meansload connected to the output end of a transmission line
ECE Board Exam March 1996Transmission lines are either balanced or unbalanced will respect to ground
ECE Board Exam March 1996What is the velocity factor for non-foam dielectric 50 or 75 ohms flexible coaxial cable such as RG 8, 11, 58, and 59?0.66
Board Exam November 1997Propagation mode of microwave in a waveguide is known as _____TE
Board Exam November 1998A transmission line consisting of two conductors that have equal resistance per unit length.Balanced line
ECE Board Exam November 1966What is the equivalent output of a circuit in dBm, if it has an output of 10 Watts?40 dBm
ECE Board Exam March 1996 Power is always ___________a definite amount of energythe rate at which energy is usedexpressed in watts
ECE Board Exam November 1998Which of the following is not a common transmission line impedance?A. 50 ohmsB. 120 ohmsC. 75 ohms
D. 650 ohms
ECE Board Exam November 1997The Width of the frequency band which is just sufficient to ensure the transmission of information of information at the rate and with the quality required under a specified condition and class of emission.Necessary bandwidth
ECE Board Exam November 1996 Transmission line must be matched to the load totransfer maximum power to the load
ECE Board Exam November 1996When electromagnetic waves are propagated through a waveguide, theyare reflected from the walls but do not travel along them
ECE Board Exam November 1997Coaxial lines are used on those system operatingBelow 2 GHz
ECE Board Exaru.November 1996 You are measuring a voice channel at a -4 dB test point level, the meter reads 73 dBm (pure test tone) convert the reading into dBrnCO.21 dBrnCO
ECE Board Exam November 19961 micron is equal to ___________ meter(s)10^-6
ECE Board Exam November 1998Best reason for pressurizing waveguides with dry air.To reduce the possibility of internal arcing
ECE Board Exam November 1997The outer conductor of a coaxial transmission line is always.grounded at theinput and output
ECE Board Exam November 1996You are measuring noise in a voice channel at 7 dB test point level. The meter reads -56 dBm
(FIA weighted). What is the reading in dBrnC?34 dBrnC
ECE Board Exam November 1998What do you call the phenomenon in digital circuits that describe the duration of time digital signal passes a circuit?Propagation delay0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Transmission Lines
Saturday, August 6, 2011
OPTICAL FIBER TRANSMISSION MEDIA (C13 Tomasi)
CHAPTER 13OPTICAL FIBER TRANSMISSION MEDIA
1)Uses light as a carrier of information.Optical communications system
2)Electronic communications system is directly proportional to bandwidth.Information-carrying capacity
3)Bandwidth of an analog communications system as a percentage of its carrier frequency.bandwidth utilization ratio
4)Device constructed from mirrors and selenium detectors that transmitted sound waves over a beam of light.Photophone
5)Experimented with an apparatus called photophone.Alexander Graham Bell
6)Used extensively in medical field.
Flexible fiberscope
7)Invented in 1960.Laser (light amplification by stimulated emission of radiation)
8)Advantages of Optical Fiber cables.1. wider bandwidth and greater information capacity2.immunity to crosstalk3. immunity to statistic interference4. environmental immunity5. safety and convenience6. lower transmission loss7. security8. durability and reliability9. economics
9)Disadvantages of Optical Fiber cables.1. interfacing cost2. strength3. remote electrical power4. optical fiber cables aremore susceptible to losses introduced by bending the cable5. specialized tools, equipment, and training
10)Reduces the possibility of the occurrence of a detrimental phenomenon.Stress corrosion
12)Protective coating.Buffer jacket
14)Increases the tensile strength of the over all cable assembly.Strength member
15)Process of decaying from one energy level to another energy level.Spontaneous decay or spontaneous emission
16)Science of measuring only light waves that are visible to human eye.Photometry
17)Measures the rate at which electromagnetic waves transfer light energy.Optical power
18)Spectral separation of white light.Prismatic refraction
19)Simply the ratio of velocity of propagation of a light ray in free space to the velocity of propagation of a light ray in a given material.Refractive index
20)Angle at which the propagating ray strikes the interface with respect to the normal.Angle of incidence
21)Angle formed between the propagating ray and the normal after the ray has entered the second medium.Angle of refraction
22)Closely related to acceptance angle and is the figure of merit commonly used to measure the magnitude of the acceptance angle.Numerical aperture
23)Simply means path.Mode
24)More than one path.Multimode
26)Probably the most important characteristic of the cable.Power loss
27)Three factors that contribute to the absorption losses in optical fibers:1. ultra violet absorption2. infrared absorption3. ion resonance absorption
28)Caused mainly by small bends and kinks in the fiber.Radiation losses
29)Caused by excessive pressure and tension and generally occur when fibers are bent during handling or installation.Contants-radius bends
30)Caused by the difference in the propagation times of light rays that take different path down a fiber.Modal dispersion
32)A p-n junction made from two different mixtures of the same types of atom.Mojunction structure
33)Generally constructed of silicon-doped gallium-arsenide.
Epitaxially grown
34)Homojunction LED’s output approximately 500 μ at a wavelength of 900 nm.Planar diffused
35) Advantages of heterojunction devices over homojunction devices;1. increase in current density generates a more brilliant light spot.2. smaller emitting area makes it easier to couple its emitted light into a fiber.3. small effective area has a smaller capacitance, which allows the planar heterojunction LED to be used at a higher speed.
36)Depletion-layer photo diode and is probably the most common device used as a light detector in fiber optic communications system.PIN diode
37)Characteristic of a light detector.1. responsivity2. dark currents3. transit time4. spectral response5. light sensitivity
ANTENNAS AND WAVEGUIDES…
ANTENNAS AND WAVEGUIDES (C15 Tomasi)
CHAPTER 15ANTENNAS AND WAVEGUIDES1)A metallic conductor system capable of radiating and capturing electromagnetic energyAntenna
2)Couples energy from a transmitter to an antenna or from antenna to a receiverTransmission Lines
3)A special type of transmission line that consists of a conducting metallic tube through which high-frequency electromagnetic energy is propagated.Waveguide
4)Electrical energy that has escaped into free space in the form of transverse electromagnetic wavesRadio Waves
5)The plane parallel to the mutually perpendicular lines of the electric and magnetic fields.Wavefront
6)The ratio of radiated to reflected energy.Radiation Efficiency
7)Antenna wherein two conductors are spread out in a straight line to a total length of one quarter wavelength.Quarter Wave Antenna
8)Another name for quarter wave antenna.Vertical Monopole or Marconi
9)A half-wave dipole.Hertz Antenna
10)A special coupling device that can be used to direct the transmit and receive signals and provide the necessary isolation.Diplexer
11)A polar diagram or graph representing field strengths or power densities at various angular positions relative to an antenna.Radiation Pattern
12)Radiation pattern plotted in terms of electric field strength or power density.Absolute Radiation Pattern
13)Radiation pattern plots field strength or power density with respect to the value at a referenceRelative Radiation
14)The primary beam of an antenna.Major Lobes
15)The major lobes that propagates and receivethe most energy.Front Lobe
16)Lobes adjacent to the front lobe.Side lobes
17)The secondary beam of an antenna.Minor Lobes
18)Lobes in a direction exactly opposite the front lobeBack Lobe
19)The ratio of the front lobe power to the back lobe power.Front to Back Ratio
20)The ratio of the front lobe to a side lobe.Front to Side Ratio
21)The line bisecting the major lobe, or pointing from the center of the antenna in the direction of maximum radiation.Line of Shoot or Point of Shoot
22)Antenna that radiates energy equally in all directions.Omni-directional Antenna
23)Radiates power at a constant rate uniformly in all directions.Isotropic Radiator
24)The direction in which an antenna is always pointing.Maximum Radiation
25)It is defined as an equivalent transmit power. It stands for Effective Isotropic Radiated Power. EIRP
26)The equivalent power that an isotropic antenna would have to radiate to achieve the same power density in the chosen direction at a given point as another antenna.Effective Radiated Power (ERP) or (EIRP)
27)The power density in space and the actual power that a receive antenna produces at its output terminals.Captured Power Density
28)It describe the reception properties of an antennaCapture Area
29)Another name for capture area.Effective Area
30)The relationship of captured power to the received power density and the effective capture area of the received antenna.Directly Proportional
31)It refers to the orientation of the electric field radiated from the antenna.Polarization
32)The angular separation between the two half-power (-3dB) points on the major lobe of an antenna's plane radiation pattern.Antenna Beamwidth
33)The frequency range over which antenna operation is satisfactory.Antenna Bandwidth
34)Another name for antenna input terminalFeedpoint
35)The feedpoint presents an ac load to the transmission line.Antenna Input Impedance
36)The simplest type of antenna. Another names for elementary doubletShort Dipole,Elementary DipoleHertzian DipoleElementary Doublet
37)Any dipole that is less than one-tenth wavelengthElectrically Short
38)Hertz antenna is name after him and he was the first to demonstrate the existence of electromagnetic waves.Heinrich Hertz
39)A single pole antenna one quarter wavelength long, mounted vertically with the lower end either connected directly to ground or grounded through the antenna coupling network.Marconi Antenna
40)Main disadvantage of Marconi Antenna.Must be close to the Ground
41)A technique use to increase the electrical length of an antennaLoading
42)A coil added in series with a dipole antenna which effectively increases antenna's electrical length.
Loading Coil
43)A loading coil approximately increases the radiation resistance of the antenna.5 Ohms
44)An individual radiator, such as a half or quarter wave dipole.Two types of antenna elementsDrivenParasiticTwo Elements of a single antennaTwo WireFolded DipoleAntenna Element
45)Its purpose is to increase the directivity and concentrate the radiated power within a smaller geographic area.Array
46)Elements that are directly connected to the transmission line and receive power from the source.Driven
47)Elements are not connected to the transmission line; they receive energy only through mutual induction with a driven element.Parasitic
48)A parasitic element that is shorter that its associated driven element.Director
49)Radiation pattern depends on the relative phase of feeds.Driven
50)The simplest type of antenna arrays.Broadside Arrays
51)A widely used antenna commonly uses a folded dipole as the driven element and named after two Japanese scientists.Yagi Uda
52)Typical directivity of a yagi-uda antenna.7 dB and 9 dB
53)Formed by placing two dipoles at right angles to each other.Turnstile Antenna
54)A class of frequency-independent antennas.Log Periodic
55)A broadband VHF or UHF antenna that is ideally suited for applications for which radiating circular rather than horizontal or vertical polarized electromagnetic waves are required.Modes of propagation:NormalAxialHelical Antenna
56)Antennas having half power beamwidths on the order of 1o or less.Three important characteristics:Front-to Back Ratio,Side-toSide CouplingBack-to-Back CouplingMicrowave Antenna
57)Antenna that provides extremely high gain and directivity and are very popular for microwave and satellite communications link.Two main partParabolic ReflectorFeed MechanismParabolic Reflector Antenna
58)The effective area in a receiving parabolic antenna and is always less than the actual mouth area.Capture Area
WIRE COMMUNICATIONS…
Wire and Wireless Communications (C7 Pastboard: Excel)
ECE Board Exam April 2001A duration of traffic path occupancy from a call, sometimes referred to as an average duration of occupancy of one or more path from calls.Holding time
ECE Board Exam November 2000Frequency band where Total Access Communication System (TACS) is allocated.935-960 MHz; 890-915 MHz
ECE Board Exam April 2000
Referred as the forward link channel of the cellular duplex systemCell to mobile unit
ECE Board Exam November 1999This referred to a condition in a telephone network where the calling party cannot get connected to the party being calledBlocked call
ECE Board Exam April 1999One of the components of a basic cellular system that handles the billing activities of the network.Mobile telephone switching office
ECE Board Exam November 1998Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz and 440 HzCall waiting tone
ECE Board Exam April 1998A multiple access technique used in GSM cellular system.TDMA
ECE Board Exam November 1997What signal-to-noise ratio is required for satisfactory telephone services?30 dB
ECE Board Exam April 1997What is the advantage of sidetone?Assures that the telephone is working
ECE Board Exam November 1996A special device circuit connecting two private branch exchanges (PBX).Tie trunkECE Board Exam March 1996The modulation system used for telegraphy isFrequency shift keying
ECE Board Exam Board April 2001Describe as the signal-to-noise ratio required to meet a satisfactory telephone service30 dB
ECE Board Exam November 2000Which of the following system uses frequency band 870-890 MHz as a transmit band of its base station?Advanced Mobile Phone Service AMPS
ECE Board Exam April 2000What third symbol in emission designation indicates cellular voice transmission?E
ECE Board Exam November 1999A term for a conventional land telephone line which is attached to the local telephone exchange by a pair of twisted copper wires.Fixed wire
ECE Board Exam April 1999A mobile telephone system, which used analogue cellular radio standard which was superceded by the Advanced Mobile Phone System in the US.IMTS
ECE Board Exam November 1998Refers to the duration occupancy period of call during its use.Holding time
ECE Board Exam April 1998How wide is the spectrum bandwidth of a single GSM carrier?200 kHz
ECE Board Exam November 1997The standard deviation of the variation in the transmission loss of a circuit should not exceed1 dB
ECE Board Exam April 1997One (1) Erlang is equal to ________.36 CCS
ECE Board Exam April 2001A type of call where cell cannot receive the supervisory audio tones in 5 seconds causing the cell site to turn the cell transceiver.Call drop
ECE Board Exam November 2000Telephone channel has a band-pass characteristics occupying the frequency range of ______300 – 3400 Hz
ECE Board Exam April 2000A digital mobile telephone system which called a European derivative of a Global System for Mobile Communication System operating at a higher frequency band.DCS-1800
ECE Board Exam 1999The receiving and transmission of printed materials over the telephone wires.
Facsimile
ECE Board Exam April 1999One of the following central office switching equipment resistance limits refers to the longest subscriber loop length.2000 ohms
ECE Board Exam April 1998The modulation technique used by GSM cellular systemGaussian Minimum Shift Keying
ECE Board Exam November 1997Nominal voice channel4 kHz
ECE Board Exam April 1997Transmission of printed material over telephone linesFacsimile
ECE Board Exam November 1996What is the transmission rate of a GSM cellular system?270 kbps
ECE Board Exam March 1996A device to be connected across the headset in telephone receivers to reduce the effects of acoustic shock.Two rectifiers in parallel with opposite polarities
ECE Board Exam April 2001The signal quality of the cells is constantly monitored by the base station, when the quality of the calls drops below a certain specified level, the base request the MTSO to try and find a better cell site is referred as _________.Hand – off
ECE Board Exam November 2000In mobile communication such as the cellular service, the current maximum power is rated at __________3 watts
ECE Board Exam April 2000A special tone frequency which is transmitted by the mobile unit to cell site signaling call termination.10 kHz
ECE Board Exam November 1999This is the Nordic analogue mobile radio telephone system originally used in Scandinavia.
NMT
ECE Board Exam April 1999An analogue mobile telephone system which was designed for United Kingdowm using 900 MHz frequency band.TACS
ECE Board Exam April 1998An interfering current in a telegraph or signaling channel due to telegraph or signaling current by another channel.Cross fire
ECE Board Exam November 1997What is the channel bandwidth of a standard analogue telephone system?300 – 3400 Hz
ECE Board Exam April 19971 – CCS is equal to100
ECE Board Exam March 1996Crosstalk coupling is ___________dBm (disturbing pair) minus dBm (disturbed pair).the difference between readings on a cable pair with a tone and a cable pair without tone read at the far end of the cable.signals from one circuit that get into another circuit
ECE Board Exam April 2001Process of automatically changing frequencies as the mobile unit transfer into a different frequency zones so that the conversation can be continued in the new zone without redialing.Hand-off
ECE Board Exam November 1996What is the diameter of a copper wire to be used in a 16 km loop with a dc loop resistance of 100 ohms/km?
ECE Board Exam April 2001Process of automatically changing frequencies as the mobile unit transfer into a different frequency zone so that the conversation can be continued in the new zone without redialing.Hand-off
ECE Board Exam November 2000A stage in cellular communication where voice channel is assigned to link up a call connection after a mobile or network originated a call.Call completion
ECE Board Exam November 1999How much approximate maximum power can a human voice possibly produce?1 milliwatt
ECE Board Exam April 1999A transmission facility connecting points 1 and 2 which is either permanent or temporary, normally voice grade facility provided by a public network provider.Channel
ECE Board Exam April 1998Best described as an amplifier used in radio telephony.Class C
ECE Board Exam November 1997Refers to the first generation of local loop system in telecommunication technologyAnalogue cellular
ECE Board Exam April 19971 Erlang is ____________1 TU
ECE Board Exam November 1996Combination of modulator, channel and detector.Discrete channel
ECE Board Exam March 1996The local loop of the telephone system is understood to beA two-wire or four-wire communication circuit between the customer’s premise and the central office.
ECE Board Exam November 1997Refers to the first generation of local loop system in telecommunication technologyAnalogue cellular
ECE Board Exam April 1997_________ is used to measure speech volumeVolume unit meter
ECE Board Exam November 1996What component in the telephone set has the primary function of interfacing the handset to the local loop?Induction coil
ECE Board Exam March 1996The ______ filter attenuates signals but passes frequencies below and above that band.Band stop
ECE Board Exam November 1996____________ is out-of-bound signaling between toll central offices (Bell System Standard)3700 Hz
ECE Board Exam March 1996In a telephone system, the customer’s telephone directory numbering is from 000 to 999, what is the capacity of the system?1,000 lines
ECE Board Exam April 2001How much signal-to-noise ratio is required to attain a satisfactory local exchange network?35 dB
ECE Board Exam April 2000What is the channel bandwidth of a standard analog telephone system?300-3400 kHz
ECE Board Exam November 1996A voice grade circuit using the PTN has an ideal passband of0 to 4 kHz
ECE Board Exam November 1996What kind of receiver is used in conventional telephone handset?Electromagnetic
ECE Board Exam April 2001In telecommunications the acronym NAM stands forNumeric assignment module
ECE Board Exam November 2000Referred as the reverse link channel of the cellular duplex system.Mobile unit to cell
ECE Board Exam April 2000Provides interface between the mobile telephone switching office and the mobile unitsCell site
ECE Board Exam November 1996What is the power loss of a telephone hybrid?3 Db
ECE Board Exam April 2001This is small radio transceiver communication device which is normally wall mounted and where the WLL subscriber plugs its telephone handset.Telephone wireless terminal
ECE Board Exam April 2000A term used in wireless telegraphy and telephony to counter irregular disturbing radiation due to various causes which is produced by arc transmitter causing a rushing sound in receiving telephones.Mush
ECE Board Exam November 1996What is the phase delay of an 800 Hz voice signal if the phase shift is 15 deg.?
ECE Board Exam November 1996A digital identification associated with a cellular systemSIM
ECE Board Exam April 2001Component of a basic cellular system that provides interface between the switching office and the mobile units.Cell site
ECE Board Exam November 2000Which of the following cellular system is the only system allowed inside United States?AMPS
ECE Board Exam April 2000Which of the following system uses frequency band 825 – 845 MHz as a receive band of it base station?Advanced Mobile Phone Services (AMPS)0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Wire communications, Wireless Communications
Tuesday, December 14, 2010
The Telephone System (Blake C8)
TRUE/FALSE
1. A telephone from 1930 could not work on today's public switched telephone network.ANS: F
2. The public switched telephone network is changing from an all analog to a mostly digital system.ANS: T
3. A LATA is a local calling area.ANS: T
4. A feature of the public switched telephone system is that calls cannot be "blocked".ANS: F
5. Telephones connect to the central office via trunk lines.ANS: F
6. The telephone switching hierarchy is being replaced by a "flat" network topology.ANS: T
7. Most local loops still use copper wire.ANS: T
8. A "twisted-pair" is twisted to minimize "crosstalk".ANS: T
9. The wires in a local loop are called TIP and GND.ANS: F
10. In a local loop, the red wire is positive.ANS: F
11. In a local loop, the TIP wire is positive.ANS: T
12. Local loops can carry voice signals in only one direction at a time.ANS: F
13. Local loops carry DC current.ANS: T
14. Local loops carry signaling information.ANS: T
15. Loading coils allow high-speed data loads to be carried on a local loop.
ANS: F
16. Typically, when a phone is on hook, a voltage of 48 volts appears across it.ANS: T
17. When a telephone is off hook, the DC voltage across it can drop substantially from its on-hook value.ANS: T
18. The DC resistance of a telephone is about 2000 ohms.ANS: F
19. When a telephone is on hook, the DC current through it is in the range of 20 to 80 mA.ANS: F
20. Touch-Tone is a registered trademark of AT&T.ANS: T
21. DTMF is the same as Touch-Tone.ANS: T
22. DTMF uses sets of 3 tones.ANS: F
23. The technology to "dial" telephone numbers was invented in 1893.ANS: T
24. A crosspoint switch allows any incoming line to be connected to any outgoing line.ANS: T
25. The central office uses 24 volts AC at 20 hertz to cause a telephone to ring.ANS: F
26. The local-loop is full-duplex.ANS: T
27. Telephones usually contain a hybrid coil or an equivalent circuit.ANS: T
28. To allow for "sidetone", a hybrid coil should be slightly unbalanced.ANS: T
29. The signal levels in analog telephone systems have increased substantially over the past 100 years.ANS: F
30. The signal levels in modern analog telephone systems are still based on 19th-century technology.ANS: T
31. To allow multiplexing, the bandwidth of voice-grade telephone signals is deliberately restricted.ANS: T
32. The net gain of a telephone system must be greater than 0 dB for an acceptable signal level.ANS: F
33. Too much gain in a telephone system causes "singing".ANS: T
34. Echo suppressors prevent oscillations on long-distance telephone circuits.ANS: T
35. Echo suppressors can be switched off by a subscriber's equipment.ANS: T
36. C-message weighting increases the bandwidth of a local loop.ANS: F
37. The reference level for measuring noise in a telephone system is 10–12 Watts.ANS: T
38. In a telephone system, signal strength is given relative to the zero transmission loss point.ANS: T
39. TDM is being replaced by the newer FDM technology in telephone systems.ANS: F
40. DS-1 can be used to carry digital data that did not originate as a voice signal.ANS: T
41. When using DS-1 to carry data, it is common to use each channel to carry 64 kbps.ANS: F
42. Digital carriers up to T3 can use copper wires.ANS: F
43. A DS-1C signal carries twice as many channels as a DS-1 signal.ANS: T
44. A DS-1C signal uses twice the bit rate of a DS-1 signal.ANS: F
45. "Stuff" bits are used to compensate for differences in clock rates.
ANS: T
46. Every "in-channel" signal is also an "in-band" signal.ANS: F
47. Common-channel signaling is being replaced by the more modern MF signaling.ANS: F
48. Common-channel signaling reduces opportunities for stealing telephone service.ANS: T
49. ADSL is faster than ISDN.ANS: T
50. B-ISDN is a slower version of standard ISDN.ANS: F
MULTIPLE CHOICE
1. DTMF stands for:a. Digital Telephony Multiple Frequency c. Dual-Tone Multifrequencyb. Dial Tone Master Frequency d. Digital Trunk Master Frequency
ANS: C
2. PSTN stands for:a. Public Switched Telephone Network c. Primary Service Telephone Networkb. Private Switched Telephone Network d. Primary Service Telephone Numbers
ANS: A
3. POTS stands for:a. Private Office Telephone System c. Primary Operational Test Systemb. Primary Office Telephone Service d. Plain Old Telephone Service
ANS: D
4. LATA stands for:a. Local Access and Transport Area c. Local Area Telephone Accessb. Local Access Telephone Area d. Local Area Transport Access
ANS: A
5. A LATA is a:a. a local calling area c. a way of accessing a tandem officeb. a type of digital local network d. a way of accessing a central office
ANS: A
6. Central offices are connected by:a. local loops c. both a and bb. trunk lines d. none of the above
ANS: B
7. Local loops terminate at:a. a tandem office c. a central officeb. a toll station d. an interexchange office
ANS: C
8. Call blocking:a. cannot occur in the public telephone networkb. occurs on the local loop when there is an electrical power failurec. occurs only on long-distance cablesd. occurs when the central office capacity is exceeded
ANS: D
9. In telephony, POP stands for:a. Post Office Protocol c. Power-On Protocolb. Point Of Presence d. none of the above
ANS: B
10. The cable used for local loops is mainly:a. twisted-pair copper wire c. coaxial cableb. shielded twisted-pair copper wire d. fiber-optic
ANS: A
11. FITL stands for:
a. Framing Information for Toll Loops c. Framing In The Loopb. Fiber In the Toll Loop d. Fiber-In-The-Loop
ANS: D
12. Loading coils were used to:a. increase the speed of the local loop for digital datab. reduce the attenuation of voice signalsc. reduce crosstalkd. provide C-type conditioning to a local loop
ANS: B
13. DC current flows through a telephone:a. when it is on hook c. as long as it is attached to a local loopb. when it is off hook d. only when it is ringing
ANS: B
14. The range of DC current that flows through a telephone is:a. 20 A to 80 A c. 2 mA to 8 mAb. 200 A to 800 A d. 20 mA to 80 mA
ANS: D
15. The separation of control functions from signal switching is known as:a. step-by-step switching control c. common controlb. crossbar control d. ESS
ANS: C
16. The typical voltage across a telephone when on-hook is:a. 48 volts DC c. 90 volts DCb. 48 volts, 20 hertz AC d. 90 volts, 20 hertz AC
ANS: A
17. The typical voltage needed to "ring" a telephone is:a. 48 volts DC c. 90 volts DCb. 48 volts, 20 hertz AC d. 90 volts, 20 hertz AC
ANS: D
18. The bandwidth of voice-grade signals on a telephone system is restricted in order to:a. allow lines to be "conditioned" c. allow signals to be multiplexedb. prevent "singing" d. all of the above
ANS: C
19. VNL stands for:a. voltage net loss c. via net lossb. volume net loss d. voice noise level
ANS: C
20. Signal loss is designed into a telephone system to:a. eliminate reflections c. improve signal-to-noise ratiob. prevent oscillation d. reduce power consumption
ANS: B
21. The reference noise level for telephony is:a. 1 mW c. 1 pWb. 0 dBm d. 0 dBr
ANS: C
22. The number of voice channels in a basic FDM group is:a. 6 c. 24b. 12 d. 60
ANS: B
23. Basic FDM groups can be combined into:a. supergroups c. jumbogroupsb. mastergroups d. all of the above
ANS: D
24. In telephone system FDM, voice is put on a carrier using:a. SSB c. PDMb. DSBSC d. PCM
ANS: A
25. PABX stands for:a. Power Amplification Before Transmissionb. Private Automatic Branch Exchangec. Public Automated Branch Exchanged. Public Access Branch Exchange
ANS: B
26. SLIC stands for:a. Single-Line Interface Circuit c. Subscriber Line Interface Cardb. Standard Line Interface Card d. Standard Local Interface Circuit
ANS: C
27. In DS-1, bits are "robbed" in order to:a. provide synchronization c. cancel echoesb. carry signaling d. check for errors
ANS: B
28. "Bit-stuffing" is more formally called:a. compensation c. justificationb. rectification d. frame alignment
ANS: C
29. ISDN stands for:a. Integrated Services Digital Network c. Integrated Services Data Networkb. Information Services Digital Network d. Information Systems Digital Network
ANS: A
30. Basic ISDN has not been widely adopted because:a. it took to long to develop
b. it is too slowc. it has been surpassed by newer technologiesd. all of the above
ANS: D
31. ADSL stands for:a. All-Digital Subscriber Line c. Allocated Digital Service Lineb. Asymmetrical Digital Subscriber Line d. Access to Data Services Line
ANS: B
32. Compared to ISDN, internet access using ADSL is typically:a. much faster c. much more expensiveb. about the same speed d. none of the above
ANS: A
COMPLETION
1. A ____________________ is a local calling area.
ANS: LATA
2. Central offices are connected together by ____________________ lines.
ANS: trunk
3. One central office can be connected to another through a ____________________ office.
ANS: tandem
4. With 7-digit phone numbers, ____________________ thousand telephones can connect to a central office.
ANS: ten
5. Call ____________________ is when it becomes impossible for a subscriber to place a call due to an overload of lines being used.
ANS: blocking
6. New ____________________ switching equipment uses TDM to combine signals.
ANS: digital
7. Most local loops still use ____________________ copper wire.
ANS: twisted-pair
8. As compared to a hierarchical network, a ____________________ network never needs more than one intermediate switch.
ANS: flat
9. ____________________ coils were used to reduce the attenuation of voice frequencies.
ANS: Loading
10. In a twisted-pair telephone cable, the red wire is called ____________________.
ANS: ring
11. In a twisted-pair telephone cable, the green wire is called ____________________.
ANS: tip
12. Of the red and green 'phone wires, the ____________________ wire is positive with respect to the other.
ANS: green
13. A telephone is said to have ____________________ the line when the central office sends it dial tone.
ANS: seized
14. The ____________________ functions are provided by a SLIC.
ANS: BORSCHT
15. A ____________________ coil prevents loss of signal energy within a telephone while allowing full-duplex operation over a single pair of wires.
ANS: hybrid
16. In a crosspoint switch, not all ____________________ can be in use at the same time.
ANS: lines
17. The old carbon transmitters generated a relatively ____________________ signal voltage.
ANS: large
18. The generic term for Touch-Tone® signaling is ____________________.
ANS: DTMF
19. A ____________________ line provides more bandwidth than a standard line.
ANS: conditioned
20. In the telephone system, amplifiers are called ____________________.
ANS: repeaters
21. An echo ____________________ converts a long-distance line from full-duplex to half-duplex operation.
ANS: suppressor
22. ____________________ weighting is an attempt to adjust the noise or signal level to the response of a typical telephone receiver.
ANS: C-message
23. In FDM telephony, the modulation is usually ____________________.
ANS: SSBSSBSC
24. In FDM telephony, ____________________ bands separate the channels in a group.
ANS: guard
25. Because of "bit robbing", a channel in a DS-1 frame allows only ____________________ kbps when used to send digital data.
ANS: 56
26. A ____________________ is a group of 12 DS-1 frames with signaling information in the sixth and twelfth frames.
ANS: superframe
27. In DS-1C, ____________________ bits are used to compensate for differences between clock rates.
ANS: stuff
28. Busy and dial tone are referred to as ____________________ signals because they use the same pair of wires as the voice signal.
ANS: in-channel
29. SS7 is the current version of _________________________ signaling.
ANS: common-channel
30. SS7 is a ____________________-switched data network.
ANS: packet
31. In ISDN, the ____________________ channel is used for common-channel signaling.
ANS: D
32. In ISDN, the ____________________ channels are used for voice or data.
ANS: B
33. Terminal equipment especially designed for ISDN is designated ____________________ equipment.
ANS: TE1
34. The A in ADSL stands for ____________________.
ANS: asymmetrical
35. In ADSL, the speed from the network to the subscriber is ____________________ than the speed in the opposite direction.
ANS: greaterfaster
SHORT ANSWER
1. For a certain telephone, the DC loop voltage is 48 V on hook and 8 V off hook. If the loop current is 40 mA, what is the DC resistance of the local loop?
ANS: 1000 ohms
2. For a certain telephone, the DC loop voltage is 48 V on hook and 8 V off hook. If the loop current is 40 mA, what is the DC resistance of the telephone?
ANS: 200 ohms
3. Which two DTMF tones correspond to the digit "1"? (Use the table in the text.)
ANS: 697 Hz and 1209 Hz
4. Calculate the dB of VNL required for a channel with a 3 ms delay.
ANS: 1 dB
5. If a telephone voice signal has a level of 0 dBm, what is its level in dBrn?
ANS: 90 dBrn
6. A telephone test-tone has a level of 80 dBrn at a point where the level is +5dB TLP. If C-weighting produces a 10-dB loss, what would the signal level be in dBrnc0?
ANS: 65 dBrnc TLP
WIRELESS COMMUNICATIONS…
Wire and Wireless Communications (C7 Pastboard: Excel)
ECE Board Exam April 2001A duration of traffic path occupancy from a call, sometimes referred to as an average duration of occupancy of one or more path from calls.Holding time
ECE Board Exam November 2000
Frequency band where Total Access Communication System (TACS) is allocated.935-960 MHz; 890-915 MHz
ECE Board Exam April 2000Referred as the forward link channel of the cellular duplex systemCell to mobile unit
ECE Board Exam November 1999This referred to a condition in a telephone network where the calling party cannot get connected to the party being calledBlocked call
ECE Board Exam April 1999One of the components of a basic cellular system that handles the billing activities of the network.Mobile telephone switching office
ECE Board Exam November 1998Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz and 440 HzCall waiting tone
ECE Board Exam April 1998A multiple access technique used in GSM cellular system.TDMA
ECE Board Exam November 1997What signal-to-noise ratio is required for satisfactory telephone services?30 dB
ECE Board Exam April 1997What is the advantage of sidetone?Assures that the telephone is working
ECE Board Exam November 1996A special device circuit connecting two private branch exchanges (PBX).Tie trunkECE Board Exam March 1996The modulation system used for telegraphy isFrequency shift keying
ECE Board Exam Board April 2001Describe as the signal-to-noise ratio required to meet a satisfactory telephone service30 dB
ECE Board Exam November 2000
Which of the following system uses frequency band 870-890 MHz as a transmit band of its base station?Advanced Mobile Phone Service AMPS
ECE Board Exam April 2000What third symbol in emission designation indicates cellular voice transmission?E
ECE Board Exam November 1999A term for a conventional land telephone line which is attached to the local telephone exchange by a pair of twisted copper wires.Fixed wire
ECE Board Exam April 1999A mobile telephone system, which used analogue cellular radio standard which was superceded by the Advanced Mobile Phone System in the US.IMTS
ECE Board Exam November 1998Refers to the duration occupancy period of call during its use.Holding time
ECE Board Exam April 1998How wide is the spectrum bandwidth of a single GSM carrier?200 kHz
ECE Board Exam November 1997The standard deviation of the variation in the transmission loss of a circuit should not exceed1 dB
ECE Board Exam April 1997One (1) Erlang is equal to ________.36 CCS
ECE Board Exam April 2001A type of call where cell cannot receive the supervisory audio tones in 5 seconds causing the cell site to turn the cell transceiver.Call drop
ECE Board Exam November 2000Telephone channel has a band-pass characteristics occupying the frequency range of ______300 – 3400 Hz
ECE Board Exam April 2000A digital mobile telephone system which called a European derivative of a Global System for Mobile Communication System operating at a higher frequency band.
DCS-1800
ECE Board Exam 1999The receiving and transmission of printed materials over the telephone wires.Facsimile
ECE Board Exam April 1999One of the following central office switching equipment resistance limits refers to the longest subscriber loop length.2000 ohms
ECE Board Exam April 1998The modulation technique used by GSM cellular systemGaussian Minimum Shift Keying
ECE Board Exam November 1997Nominal voice channel4 kHz
ECE Board Exam April 1997Transmission of printed material over telephone linesFacsimile
ECE Board Exam November 1996What is the transmission rate of a GSM cellular system?270 kbps
ECE Board Exam March 1996A device to be connected across the headset in telephone receivers to reduce the effects of acoustic shock.Two rectifiers in parallel with opposite polarities
ECE Board Exam April 2001The signal quality of the cells is constantly monitored by the base station, when the quality of the calls drops below a certain specified level, the base request the MTSO to try and find a better cell site is referred as _________.Hand – off
ECE Board Exam November 2000In mobile communication such as the cellular service, the current maximum power is rated at __________3 watts
ECE Board Exam April 2000A special tone frequency which is transmitted by the mobile unit to cell site signaling call termination.
10 kHz
ECE Board Exam November 1999This is the Nordic analogue mobile radio telephone system originally used in Scandinavia.NMT
ECE Board Exam April 1999An analogue mobile telephone system which was designed for United Kingdowm using 900 MHz frequency band.TACS
ECE Board Exam April 1998An interfering current in a telegraph or signaling channel due to telegraph or signaling current by another channel.Cross fire
ECE Board Exam November 1997What is the channel bandwidth of a standard analogue telephone system?300 – 3400 Hz
ECE Board Exam April 19971 – CCS is equal to100
ECE Board Exam March 1996Crosstalk coupling is ___________dBm (disturbing pair) minus dBm (disturbed pair).the difference between readings on a cable pair with a tone and a cable pair without tone read at the far end of the cable.signals from one circuit that get into another circuit
ECE Board Exam April 2001Process of automatically changing frequencies as the mobile unit transfer into a different frequency zones so that the conversation can be continued in the new zone without redialing.Hand-off
ECE Board Exam November 1996What is the diameter of a copper wire to be used in a 16 km loop with a dc loop resistance of 100 ohms/km?
ECE Board Exam April 2001Process of automatically changing frequencies as the mobile unit transfer into a different frequency zone so that the conversation can be continued in the new zone without redialing.Hand-off
ECE Board Exam November 2000A stage in cellular communication where voice channel is assigned to link up a call connection after a mobile or network originated a call.Call completion
ECE Board Exam November 1999How much approximate maximum power can a human voice possibly produce?1 milliwatt
ECE Board Exam April 1999A transmission facility connecting points 1 and 2 which is either permanent or temporary, normally voice grade facility provided by a public network provider.Channel
ECE Board Exam April 1998Best described as an amplifier used in radio telephony.Class C
ECE Board Exam November 1997Refers to the first generation of local loop system in telecommunication technologyAnalogue cellular
ECE Board Exam April 19971 Erlang is ____________1 TU
ECE Board Exam November 1996Combination of modulator, channel and detector.Discrete channel
ECE Board Exam March 1996The local loop of the telephone system is understood to beA two-wire or four-wire communication circuit between the customer’s premise and the central office.
ECE Board Exam November 1997Refers to the first generation of local loop system in telecommunication technologyAnalogue cellular
ECE Board Exam April 1997_________ is used to measure speech volumeVolume unit meter
ECE Board Exam November 1996What component in the telephone set has the primary function of interfacing the handset to the local loop?Induction coil
ECE Board Exam March 1996The ______ filter attenuates signals but passes frequencies below and above that band.Band stop
ECE Board Exam November 1996____________ is out-of-bound signaling between toll central offices (Bell System Standard)3700 Hz
ECE Board Exam March 1996In a telephone system, the customer’s telephone directory numbering is from 000 to 999, what is the capacity of the system?1,000 lines
ECE Board Exam April 2001How much signal-to-noise ratio is required to attain a satisfactory local exchange network?35 dB
ECE Board Exam April 2000What is the channel bandwidth of a standard analog telephone system?300-3400 kHz
ECE Board Exam November 1996A voice grade circuit using the PTN has an ideal passband of0 to 4 kHz
ECE Board Exam November 1996What kind of receiver is used in conventional telephone handset?Electromagnetic
ECE Board Exam April 2001In telecommunications the acronym NAM stands forNumeric assignment module
ECE Board Exam November 2000Referred as the reverse link channel of the cellular duplex system.Mobile unit to cell
ECE Board Exam April 2000Provides interface between the mobile telephone switching office and the mobile unitsCell site
ECE Board Exam November 1996What is the power loss of a telephone hybrid?3 Db
ECE Board Exam April 2001This is small radio transceiver communication device which is normally wall mounted and where the WLL subscriber plugs its telephone handset.Telephone wireless terminal
ECE Board Exam April 2000A term used in wireless telegraphy and telephony to counter irregular disturbing radiation due to various causes which is produced by arc transmitter causing a rushing sound in receiving telephones.Mush
ECE Board Exam November 1996What is the phase delay of an 800 Hz voice signal if the phase shift is 15 deg.?
ECE Board Exam November 1996A digital identification associated with a cellular systemSIM
ECE Board Exam April 2001Component of a basic cellular system that provides interface between the switching office and the mobile units.Cell site
ECE Board Exam November 2000Which of the following cellular system is the only system allowed inside United States?AMPS
ECE Board Exam April 2000Which of the following system uses frequency band 825 – 845 MHz as a receive band of it base station?Advanced Mobile Phone Services (AMPS)0 comments Email This BlogThis! Share to Twitter Share to Facebook Labels: Communications, Excel, Past Board, Wire communications, Wireless Communications
Tuesday, February 1, 2011
Paging and Wireless Data Networking (Blake C23)
TRUE/FALSE
1. Traditional paging systems use low-power transmitters.
ANS: F
2. Traditional paging systems use widely spaced transmitters.
ANS: T
3. Pagers use the VHF band.
ANS: T
4. Pagers use the UHF band.
ANS: T
5. Pager messages typically require a lot of bandwidth.
ANS: F
6. Each pager has a unique address.
ANS: T
7. Typically, pager systems keep track of each pager's location.
ANS: F
8. Satellite systems are used by pagers.
ANS: T
9. All pagers are one-way only.
ANS: F
10. Wireless LANs are typically slower than wired LANs.
ANS: T
11. Wireless LANs are typically more expensive than wired LANs.
ANS: T
12. The IEEE 802.33 covers wireless LANs.
ANS: F
13. Few companies actually use the IEEE 802 wireless LAN specifications.
ANS: F
14. Wireless LANs typically use a spread-spectrum modulation.
ANS: T
15. IEEE 802 allows up to 1 watt of transmitter power.
ANS: T
16. The typical range of a wireless LAN in an office environment is about 10 meters.
ANS: F
17. The range of a Bluetooth system in an office environment is about 0.01 meters to 10 meters.
ANS: T
18. Any Bluetooth device should be able to communicate with any other Bluetooth device.
ANS: T
19. Bluetooth has a channel bit rate of 100 Mbps.
ANS: F
20. Bluetooth devices communicate automatically once they are in range of each other.
ANS: T
21. Bluetooth uses spread-spectrum modulation.
ANS: T
22. Bluetooth uses frequency hopping.
ANS: T
23. Bluetooth is designed for audio as well as data.
ANS: T
24. Currently, no wireless LAN uses light-wave transmission.
ANS: F
25. A wireless LAN based on light waves would need direct line of sight for connections.
ANS: F
MULTIPLE CHOICE
1. Pagers use:a. the VHF band onlyb. the UHF band onlyc. both the VHF and UHF bandsd. the VHF band, the UHF band, and the ISM band
ANS: C
2. ISM stands for:a. IEEE Standard Message c. Industrial, Scientific, and Messagingb. IEEE Secure Message d. Industrial, Scientific, and Medical
ANS: D
3. CAPCODE is:a. an encryption scheme used for pagersb. an addressing scheme used for pagersc. an error-detection scheme used for pagersd. a digital modulation scheme used for pagers
ANS: B
4. In a one-way pager system:a. all pages are sent from all transmittersb. each transmitting antenna covers a wide areac. transmitters use relatively high powerd. all of the above
ANS: D
5. POCSAG stands for:a. Pager Operations Common Standards Advisory Groupb. Pager Operations Code Standardization Advisory Groupc. Post Office Code Standardization Advisory Groupd. Post Office Common Standards Advisory Group
ANS: C
6. A typical pager system does not:a. require "handoffs" c. require error detectionb. allow "roaming" d. all of the above
ANS: A
7. The IEEE specification covering wireless LANs is:a. 802.10 c. 802.12b. 802.11 d. 802.13
ANS: B
8. The IEEE 802 spec for wireless LANs uses the:a. VHF band c. ISM bandb. UHF band d. infrared band
ANS: C
9. The IEEE 802 document for wireless LANs specifies the use of:a. CSMA/CA c. CDMAb. CSMA/CD d. all of the above
ANS: A
10. BSS stands for:a. Basic Service Set c. Bluetooth Service Systemb. Basic Service System d. none of the above
ANS: A
11. Bluetooth uses:a. CDMA c. QPSK
b. frequency hopping d. all of the above
ANS: B
12. Bluetooth uses the:a. VHF band c. ISM bandb. UHF band d. infrared band
ANS: C
13. TDD stands for:a. Time-Division Duplex c. Time Delay Differenceb. Time-Delayed Duplex d. Total Distance Delay
ANS: A
14. A Bluetooth "piconet" has:a. 2 nodes c. 2 to 8 nodesb. 2 to 4 nodes d. 2 to 16 nodes
ANS: C
15. Two or more connected piconets forms a:a. micronet c. TDD netb. multinet d. scatternet
ANS: D
16. The basic range of a Bluetooth device is:a. 10 cm to 1 meter c. 10 cm to 100 metersb. 10 cm to 10 meters d. within 10 feet
ANS: B
17. IRDA stands for:a. Infrared Data Association c. Infrared Restricted Data Areab. Infrared Digital Association d. Infrared Roaming Data Area
ANS: A
18. The range of an IRDA system is:a. 1 meter c. 1 footb. 10 meters d. 10 feet
ANS: A
19. Infrared networks:a. cannot penetrate walls c. can use reflected infrared beamsb. can use diffused infrared beams d. all of the above
ANS: D
20. The maximum range of a typical wireless modem is:a. 1 meter c. several hundred metersb. several meters d. several thousand meters.
ANS: D
COMPLETION
1. Each pager has a unique address called a ____________________.
ANS: capcode
2. Many pagers can share a frequency using ____________________.
ANS: TDMA
3. The POCSAG was devised by the British ____________________ Office.
ANS: Post
4. A POCSAG message uses a ____________________-bit error correction code.
ANS: 10
5. IEEE ____________________ covers wireless LANs.
ANS: 802.11
6. The IEEE document specifies a maximum power of ____________________ for wireless LANs.
ANS: 1 watt
7. Bluetooth uses the ____________________ band.
ANS: ISM
8. A network of 2 to 8 Bluetooth devices is called a ____________________.
ANS: piconet
9. A Bluetooth scatternet consists of 2 or more ____________________.
ANS: piconets
10. An IRDA system is deliberately restricted to a range of ____________________.
ANS: 1 meter