basic ac quiz

7/28/2019 Basic AC Quiz

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Fill in the blank values based on the information provided

1)

Peak to peak voltage 12 Volts AC

RMS voltage (effective):

FrequencyWave length (meters)

Time for 1 cycle 20 micro seconds

2)

Peak voltage

RMS voltage (effective): 15 Kilo-Volts AC

Frequency 250 Hz

Wave length (meters)

Time for 1 cycle

3) List three advantages of alternating current over direct currenta. _____________________________________b. _____________________________________c. ___________________________________


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4) What is the effective current of the circuit below?

5) What is the effective power of the circuit bellow?

6) What is the peak power dissipated by the circuit below?

7) What is the True power dissipated by the circuit above?


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8) What is the reactance of a 1 F capacitor at the following frequencies?

60 Hz? _______________

1 kHz? _______________

9) What type of filter is illustrated below this question?


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10) What frequencies will the circuit below pass to meter ?

_________________________

11) What frequencies will the circuit below pass to the acvoltmeter?

_____________________________

5 micro Farads

1000 Ohms

S

G

signal generator

METER

AC Voltmeter

5 pico Farads

10K Ohms

S

G

signal generator

METER

AC Voltmeter


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13)(8 Pts)What is the impedance of a network composed of a 500mili-henry inductor inseries with a 100-ohm resistor and a 25 micro-farad capacitor , at 67.8 Hz? Specifyyour answer in rectangular coordinates and Polar coordinates.

Polar Coordinates___________________________________________________

Rectangular Coordinates ______________________________________________


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14)(8 Pts) What is the impedance of a network comprised of a 150-ohm-reactanceinductor with a 2300-ohm resistor and a 200 ohm-reactance capacitor all in parallel?

Polar Coordinates___________________________________________________

Rectangular Coordinates ______________________________________________


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15)

Given the Oscillator schematic above,

What is the frequency determining device?_______________________

What is the regenerative feedback path?_________________________

What Components develop the output for Q2?____________________


What components set up bias for Q2?___________________________


What function does C1 perform?______________________________


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16)

Given the Oscillator schematic above, What components form the

frequency determining

device?___________________________________________________

What is the regenerative feedback path?_________________________



What function does C4 perform?______________________________

What function does R3 perform?______________________________


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17)

Identify filter type (L, Pi, T) and function (low pass,

High Pass, band pass, band reject)

____________ _______________

____________ ___________________

______________ __________________

_______________

_________________

____________ _______________


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18)

Given the circuit above, resistor value is 100 ohms and capacitor value is 2 micro farads

What is the cut-off frequency for the circuit above?

What is the current?

What is the voltage drop of the capacitor?


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19) Which statement is true regarding the filter output characteristics shown in Figure

3F16?

A. C is a high pass curve and B is a band pass curve.B. B is a high pass curve and D is a low pass curve.

C. A is a high pass curve and B is a low pass curve.

D. B is a band pass curve and C is a low pass curve.

20)

21) List 4 requirements for an oscillator circuit:

1) _______________________

2) _______________________

3)_______________________4)_______________________


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input to a mixer is 200 MHz and the local oscillator frequency is 150 MHz. What output wouldyou expect to see at the IF output prior to any filtering?

A. 50, 150, 200 and 350 MHz.B. 50 MHz.

C. 350 MHz.

D. 50 and 350 MHz.

2) If a single side band SSB transmitter radiates 1000 watts at peak modulation, what willit radiate with no modulation?

A. 10 WattsB. 0 WattsC. 500 WattsD. 1000 Watts

3) Describe the function of the six major components of receiving andprocessing a radio transmission. Number the processes in order necessary to

receive an amplitude modulated radio frequency and produce an audio signal.

___Preamplifier___________________________________________________________

___Demodulator__________________________________________________________

___Speaker or video/signal processor________________________________________

___Antenna_____________________________________________________________

___Antenna coupler_______________________________________________________

___Tuner________________________________________________________________

___Audio Power amplifier__________________________________________________

4) Is the modulation function accomplished as part of the transmit or receiveprocess?

5) Under normal circumstances, when frequencies are above 30 MHz, whatinfluence does the ionosphere have on them?


13/19

6) Long range HF radio communications are primarily enables by which layers ofthe ionosphere?

7) When is the D layer of the ionosphere most prevalent? What affect does it haveon HF sky-waves?

8) Class A amplifiers conduct what percentage?

9) When comparing class A, class B, and Class C amplifiers, which class ofamplifier is the most efficient?

10-13 Answer true or false

10)_______Frequencies in the UHF band are typically used for long range

communications because the short wave length tends to bounce off the ionosphere.

11)_______The F1 and F2 layers of the Ionosphere are not important to long range sky

wave radio communications.

12)_______Class AB amplifiers are more efficient than class B amplifiers

13)_______An antenna coupler is an impedance matching device that matches theantenna system impedance to the frequency being utilized

14) What will over-modulation of an AM signal cause?

15) What are the four minimum components of an oscillator?

16) What are the frequency determining components in the circuit below?


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17) What is the purpose of a buffer amplifier between a mixer circuit and an oscillator?

18) What is the frequency determining device (FDD) in the circuit below?

19) What type of waveform is produced by a sinusoidal oscillator?a. Sine Waveb. Squad wavec. Pulsesd. Saw tooth

20) What is the interchange of energy between the inductor and capacitorin a tank circuit used as an FDD called?


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21) What components (s) in the circuit below keep the oscillator frequencyfrom entering the power supply?

22) What components forward bias Q1 in the circuit below?

Write the type of modulation in the blank provided23) _________________________


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Write the type of modulation in the blank provided

24)___________________________________

25)What type of modulation is represented in the signalbelow?____________________________


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26) Given binary modulating source (line A), enter the type of modulationrepresented on lines B, C and D.


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27)List the 6 minimum processes in a radio transmitter in blockdiagram form, starting with the microphone and ending with the

antenna. Ensure you explain the function of each process.


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basic ac quiz

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