short notes _ eee press.pdf

9/4/2015 Short Notes | EEE PRESS

data:text/html;charset=utf8,%3Ch1%20class%3D%22entrytitle%22%20style%3D%22margin%3A%200px%200px%205px%3B%20padding%3A%200px%3… 1/20

Short NotesWritten by admin | May 11, 2015 | Comments Off on Short Notes

Electric Current and Ohm’s LawMultiple Choice Questions of Electric Currentand Ohm’s Law (115):1. Resistivity of a wire depends on(A) length(B) material(C) cross section area(D) none of the above.

2. When n resistances each of value r areconnected in parallel, then resultantresistance is x. When these n resistances areconnected in series, total resistance is

(A) nx(B) rnx(C) x / n(D) n2 x.

3. Resistance of a wire is r ohms. The wire isstretched to double its length, then itsresistance in ohms is

(A) r / 2(B) 4 r(C) 2 r(D) r / 4.

5. The diameter of the nucleus of an atom isof the order of

(A) 10 31 m(B) 10 25 m(C) 10 21 m(D) 10 14m.

6. The mass of proton is roughly how manytimes the mass of an electron?

(A) 184,000(B) 184,00(C) 1840(D)184.

7. The charge on an electron is known to be1.6 x 1019 coulomb. In a circuit the currentflowing is 1 A. How many electrons will beflowing through the circuit in a second?

(A) 1.6 x 1019(B) 1.6 x 1019

11. One kilowatt hour of electrical energy is thesame as(A) 36 x 105 watts(B) 36 x 10s ergs(C) 36 x 105 joules(D) 36 x 105 B.T.U.

12. An electric current of 5 A is same as

(A) 5 J / C(B) 5 V / C(C) 5 C / sec(D) 5 w / sec.

13. An electron of mass m kg and having acharge of e coulombs travels from rest through apotential difference of V volts. Its kinetic energywill be (A) eV Joules(B) meV Joules(C)me / V Joules(D)V / me Joules.

14. The value of the following is given by 100(kilo ampere ) x ( micro ampere ) 100 milliampere * 10 ampere

(A) 0.001 A(B) 0.1 A(C) 1 A(D) 10A.

15. A circuit contains two unequal resistances inparallel

(A) current is same in both(B) large current flows in larger resistor(C) potential difference across each is same(D) smaller resistance has smaller conductance.

16.Conductance is expressed in terms of(A) ohm / m(B) m / ohm(C) mho / m(D) mho.

17. Which of the following could be the value ofresistivity of copper?

(C) 0.625 x 1019(D) 0.625 x 1012.

8. Two bulbs marked 200 watt250 volts and100 watt250 volts are joined in series to 250volts supply. Power consumed in circuit is

(A) 33 watt(B) 67 watt(C) 100 watt(D) 300 watt.

9. Ampere second could be the unit of

(A) power(B) conductance(C) energy(D) charge.

10. Which of the following is not the same aswatt?

(A) joule/sec(B) amperes/volt(C) amperes x volts(D) ( amperes )2 x ohm.

(A) 1.7 x 108 ohmcm(B). 1.7 x 106 ohmcm(C). 1.6 x 105 ohmcm(D). 1.7 x 104 ohmcm

18. A copper wire of length l and diameter d haspotential difference V applied at its two ends.The drift velocity is vd. If the diameter of wire ismade d/3, then drift velocity becomes

(A) 9 vd(B) vd / 9(C)vd /3(D)vd.

19.Two resistances R1 and R2 give combinedresistance of 4.5 ohms when in series and 1 ohmwhen in parallel. The resistances are

(A)3 ohms and 6 ohms(B)3 ohms and 9 ohms(C)1.5 ohms and 3 ohms(D)1.5 ohms and 0.5 ohms.

20. We have three resistances of values 2 Ω,3 Ω and 6 Ω. Which of the followingcombination will give an effective resistanceof 4 Ω?(A) All the three resistances in parallel(B) 2 Ω resistance in series with parallelcombination of 3 Ω and 6 Ω resistance(C) 3 Ω resistance in series with parallelcombination of 2 Ω and 6 Ω resistance(D) 6 Ω resistance in series with parallelcombination of 2 Ω and 3 Ω resistance.

21. Three equal resistors connected in seriesacross a source of emf together dissipate 10watts of power. What would be the powerdissipated in the same resistors when theyare connected in parallel across the samesource of emf?

(A) 10 watts(B) 30 watts(C) 90 watts(D) 270 watts.

22.Current I in the figure is

33.Five resistances are connected as shown infigure below. The equivalent resistance betweenthe points A and B will be

(A) 35 ohms(B) 25 ohms(C) 15 ohms(D) 5 ohms.34.How many different combinationsmay be obtained with three resistors, eachhaving the resistance R ?

(A)1.5A(B)0.5A(C)3.5A(D)2.5A23.Four identical resistors are firstconnected in parallel and then in series. Theresultant resistance of the first combination tothe second will be

(A) 1 / 16 times(B) 1 / 4 times(C) 4 times(D) 16 times.

24.Twelve wires of same length and samecrosssection are connected in the form of acube as shown in figure below. If theresistance of each wire is R, then the effectiveresistance between P and Q will be

(A)R(B) 5 / 6 R(C) 3 / 4 R(D) 4 / 3 R.25. When P = Power, V = Voltage,I = Current, R = Resistance and G =Conductance, which of the following relationis incorrect?

(A) V = √ (PR)(B). P= V2G(C) G= P / I2(D) I =√ (P / R)

26.The unit of electrical conductivity is

(A) 3(B) 4(C) 5(D) 6.

35.A wire of 0.14 mm diameter and specificresistance 9.6 micro ohmcm is 440 cm long. Theresistance of the wire will be

(A) 9.6 ohm(B) 11.3 ohm(C) 13.7 ohm(D) 27.4 ohm.

36.Ohm’s law is not applicable to

(A) DC circuits(B) high currents(C) small resistors(D) semiconductors.

37.A metal resistor has resistance of 10 ohm at0°C and 11 ohms at 160°C, the temperaturecoefficient is

(A) 0.00625 / °C(B) 0.0625 /°C(C) 0.000625 /°C(D) 0.625 /°C.

Questions 38 to 40 refer to Figure givenbelow.

Five resistances are connected as shown andthe combination is connected to a 40 Vsupply.38. Voltage between point P and Q will be

(A) 40 V(B) 22.5 V(C) 20 V(D) 17.5 V.

39.The current in 4 ohm resistor will be

(A) 2.1 A(B) 2.7 A(C) 3.0 A

(A) mho / metre(B) mho / sq. m(C) ohm / metre(D) ohm / sq. m.

27.Which of the following bulbs will have theleast resistance ?

(A) 220 V, 60 W(B) 220 V, 100 W(C) 115 V, 60 W(D) 115 V, 100 W.

28.The ratio of the resistance of a 100 W, 220V lamp to that of a 100 W, 110 V lamp will benearly

(A) 4(B)2(C) 1 / 2(D) 1 / 4

29.The resistance of a 100 W, 200 V lamp is

(A) 100 ohm(B) 200 ohm(C) 400 ohm(D) 1600 ohm.

30.Two 1 kilo ohm, 1/2 W resistors areconnected in series. Their combinedresistance value and wattage will be

(A) 2 kΩ, 1/2 W(B) 2 kΩ, 1 W(C) 2 kΩ, 2 W(D) l kΩ, 1/2 W.

31.Which method can be used for absolutemeasurement of resistances ?

(A)Ohm’s law method(B)Wheatstone bridge method(C)Releigh method(D) Lortentz method.

32.Three 3 ohm resistors are connected toform a triangle. What is the resistancebetween any two of the corners?

(A) 3 / 4 ohms(B) 3 ohms(C) 2 ohms(D) 4/3 ohm.

(D) 3.5 A.

40.Least current will flow through

(A) 25 ohm resistor(B) 18 ohm resistor(C) 10 ohm resistor(D) 5 ohm resistor.

41.Total power loss in the circuit is

(A)10W(B) 50.2 W(C) 205 W(D) 410 W.

42.A resistance of 5 ohms is further drawn sothat its length becomes double. Its resistance willnow be

(A) 5 ohms(B) 7.5 ohms(C) 10 ohms(D) 20 ohms.

43.Specific resistance of a substance ismeasured in

(A) ohms(B) mhos(C) ohmcm(D) cm/ohm.

44.A wire of resistance R has it length and crosssection both doubled. Its resistance will become

(A) 4 R(B)2 R(C) R(D) R / 4.

45.Ohm’s law is not applicable in all the followingcases Except

(A) Electrolytes(B) Arc lamps(E) Insulators(A) Vacuum ratio values.

56.A standard 60 W bulb is in series with a

46.The element of electric heater is made of(A)copper(B) steel(C) carbon(D) nichrome.

47. 5xl016 electrons pass across the section of aconductor in 1 minute 20 sec. The current flowingis

(A) 1mA(B) 0.1 mA(C) 0.01mA(D) 10 mA.

48.Which of the following figures represents theeffect of temperature on resistance for copper ?

(A) figure A(B) figure B(C) figure C(D) figure D.49.Three elements havingconductance G1, G2 and G3 are connected inparallel. Their combined conductance will be

(A) 1/( 1/G1 + 1/G2 + 1/G3)(B) (G1G2 + G2G3 + G3G1)/(G1 + G2 + G3)(C) 1/(G1 + G2+ G3)(D) G1 + G2 +G3

Questions 50 to 53 refer to Figure givenbelow:

room heater and connected across the mains.If the 60 W bulb is replaced by 100 W bulb(A)the heater output will increase(B) the heater output will reduce(C) the heater output will remains unaltered.

57. Two aluminium conductors have equallength. The crosssectional area of oneconductor is four times that of the other. If theconductor having smaller crosssectional areahas a resistance of 100 ohms the resistanceof other conductor will be

(A) 400 ohms(B) 100 ohms(C) 50 ohms(D) 25 ohms.

58.A nichrome wire used as heater coil hasthe resistance of 1 ohm/m. For a heater of1000 W at 200 V, the length of wire requiredwill be

(A) 10 m(B) 20 m(C) 40 m(D) 80 m.

59.The hot resistance of a tungsten lamp isabout 10 times the cold resistance.Accordingly, cold resistance of a 100 W, 200V lamp will be (A) 4000 ohm

(B)400 ohm(C)40 ohm(D)4 ohm.

60. Variable resistors are

(A)Wire wound resistors(B)Thin film resistors(C)Thick film resistors(D)All of the above.

61.Low resistance can be accuratelymeasured by

(A) Kelvin bridge(B )Wheat stone bridge(C) Wein’s bridge(D) None of the above.

62.A heating element of a hot plate on anelectric cooking range draws 12 amperesfrom 240 V mains. How many kWh of energy

50.The variation of resistance of iron and somealloys with temperature is shown in figure. Thevariation of carbon will be represented by(A)curve A(B) curve B(C) curve C(D) curve D.

51.Curves A and B represent the properties formaterials which have

(A) low resistance(B) low conductance(C) negative resistance(D) negative temperature coefficient.

52.Which of the following has negativetemperature coefficient ?

(A) Brass(B) Mercury(C) Electrolytes(D) Silver.

53.All of the following have negative temperaturecoefficient EXCEPT

(A) Paper(B) Gold(C) Rubber.

54.For the circuit shown below the current Iflowing through the circuit will be

will be consumed in one hour and 15 minutes

(A) 1.2(B) 3.2(C) 6.0

63. Temperature coefficient of resistance isexpressed in terms of

(A) ohms / ohms oC(B) mhos / ohm oC(C) mhos / oC(D) ohms / oC.

64. If R1 is the resistance of a coil of copperat t oC and RT is the resistance at T oC andalso the resistance temperature coefficient ofcopper per degree centrigrade at 0oC is1/234.45, then Rt/RT

(A) (1+t) / (1+T)(B) (1+ 234.45t) / (1+234.45 T)(C) (234.45 + t) / (234.45 + T)(D) (234.45 + t2 ) / (234.45 + T 2).

65. Resistivity is usually expressed in terms of

(A) mho(B) ohm / oC(C) ohms/cmsquare(D) ohms/cmcube.

66. Which material is expected to have leastresistivity?

(A) Copper(B) Lead(C) Mercury(D) Zinc.

67. The shunt winding of a motor has aresistance of 85 ohm at 22oC. When themotor runs at full load, its resistanceincreases to 100 ohms. The resistancetemperature coefficient of winding per 0oC is0.004. The rise in temperature of the windingwill be nearly

(A) 20oC(B) 50oC(C)70oC(D) 100oC.

68. The resistance temperature coefficient isdefined as

(A)1 / 2 A(B) 1 A(C) 2 A(D) 4 A.55.A cube of material of side 1 cm has aresistance of 0.002 ohm between its oppositefaces. If the same volume of the material has alength of 8 cm and a uniform crosssection, theresistance of this length will be

(A) increase in resistance per degreecentigrade(B) decrease in resistance per degreecentigrade(C) the ratio of increase in resistance perdegree centigrade to the resistance at 0oC(D) the ratio of increases in resistance perdegree centigrade to the rate of rise ofresistance at 0oC.

69.Two coils connected in series haveresistance of 600 ohm and 300 ohm andtemperature coefficients of 0.1% and 0.4%respectively.The resistance of thecombination at 50oC will be

(A) 1050 ohm(B)1001 ohm(C)1600 ohm(D) 990 ohm.

70. A 100 W, 200 V filament lamp hasoperating temperature of 2000oC. Thefilament material has resistancetemperature coefficient of 0.005 at 0oCper oC. The current taken by the lamp atthe instant of switching with 200 V supplywith filament temperature of 20oC willbe(A) 1 A(B) 3 A(C) 5 A(D)10A.

71. A fuse is always installed in a circuit is

(A) Series(B) Parallel.

72. The rating of fuse wire is expressed interms of

(A) Ohms(B) Mhos(C) Amperes(D) Watts.

73. Which of the following material is notused as fuse material?

76. The current through 6 ohm resistor will be(A) 1 A(B) 2 A(C) 3 A(D) 4 A.

77. The ratio of power dissipated in circuit ADB tothat in circuit ABC will be

(A) 1(B) 1.5

(A) Silver(B) Copper(C) Aluminium(D) Carbon.

Questions 74 to 78 refer to Figurebelow.

74. The voltage drop across the resistor 9ohm will be(A)18 V(B) 12 V(C) 9 V(D) 6 V.

75. The voltage drop will be least in whichresistor ?

(A) 2 ohm(B) 3 ohm(C) 6 ohm(D) 3 ohm and 6 ohm.

(C)0.67(D) 2.

78. Total power dissipated in the circuit is

(A) 80 W(B)100 W(C)120 W(D) 150 W.

79. The current carrying capacity of the fusematerial depends on

(A) crosssectional area(B) length(C) material(D) all of the above.

80. According to the fuse law, the current carryingcapacity varies as

(A) diameter(B) (diameter)3/2(C) 1 / diameter(D)1 / (diameter)2.

Questions 81 to 83 refer to Figure givenbelow.

81. For the circuit shown in Figure above, thevalue of current I will be(A) 10A(B) 15A(C) 20A(D) 25A

82. The combined resistance of the circuit is

83. Total power dissipated in the circuit is

91. 40 W bulb A will be least bright when(A)only keys k1 and k2 are open(B) only keysk2 is open(C) only keys k3 is open(D) all keys are closed.

92. The power consumption of the circuit willbe maximum when

(A) key k1 and k3 are closed and k2 is open(B) key k1 is closed, k2 and k3 are open

(A) 2.5 kW(B) 5.0 kW(C) 7.5 kW(D)10 kW.

84. A 100 W bulb is connected in series with aroom heater of 750 W. What will happen if thebulb is replaced by a 60W bulb?

(A) Heater output will increase(B) Heater output will decrease(C) Heater output will remain unchanged(D) Bulb will not glow.

85. An immersion rod heats a bucket of water in15 minutes. In order that the water should boil in10 minutes

(A) length of heating element of the rod shouldbe increased(B) length of heating element of the rod shouldbe reduced(C) supply voltage should be reduced(D) heating element of larger diameter should beused.

86. A lamp of 100 W at 200 V is supplied currentat 100 volts. It will be equivalent to the lamp of

(A) 50 W(B) 40 W(C) 25 W(D) 10 W.

87. Two electric bulbs of 100 W, 200 V are putin series and the combination is supplied 100 V.The power consumption of each bulb will be

(A) 100 / 2 W(B) 100 / 4 W(C) 100 / 8 W(D) 100 / 16 W.

(C) key k1 and k2 are closed and k3 is open(D) all the keys are closed.

93. Which of the following lamps will haveleast resistance at room temperature ?

(A) 200 W, 220 V(B) 100 W, 220 V(C) 60 W, 220 V(D) 25 W, 220 V.

94. Filaments of electric bulbs are usuallymade of

(A) Nichrome(B) Tungsten(C) Copper(D) Carbon.

95. The value of supply voltage for 500 W ,5ohm load is

(A) 500 V(B) 100V(C) 50 V(D) 10V.

96. Which resistor will be physically larger insize ?

(A)10 ohm, 50 W(B) 100 ohm, 10 W(C) 1 kohm, 1 W(D) 10 Mohm, 1/ 2 W.

97. Four resistances R1 , R2, R3 and R4 areconnected in series against 220 V supply. Theresistances are such that R1 > R2 > R3 > R4.The least power consumption will be in

(A) resistor R1(B) resistor R2(C) resistor R3(D) resistor R4.

98. 100 resistors of 100 ohms each arcconnected in parallel. Their equivalentresistances will be

(A) 10,000 ohms(B) 100 ohms(C) 1 ohm(D) 1/ 10000 ohm.

99. For a fixed supply voltage the currentflowing through a conductor will decrease

88. Three lamps are in circuit as shown inFigure given above. The lamp of 100 W willhave maximum brightness when(A) key k1 isclosed, k2 is open and k3 is closed(B) k1 is open, k2 is closed and k3 is open(C) k1 is open, k2 is closed and k3 is alsoclosed(D) k1 is closed, k2 is open and k3 is also open.

89. When switches k1 and k2 are open and k3 isclosed

(A) 100 W lamp will glow brighter than 40 Wlamp(B) 40 W lamp will glow brighter than 100 Wlamp(C) Both will glow at their full brightness(D) Both will glow at less than their fullbrightness.

90. Which of the following statements isnecessarily correct ?

(A) 40 W bulbs will always glow at full brightness(B) 100 W bulb will always glows at fullbrightness(C) Whatever be the position of keys, at leastone 40 W bulb will always glow(D) Whenever current flows through the circuit,100 W bulb will always glow.

(A) crosssectional area of the conductor isincreased(B) length of the conductor is increased(C) length of the conductor is reduced(D) crosssectional area is increased andlength is decreased.

100.When current flows through heater coil itglows but supply wiring does not glowbecause

(A) supply wiring is covered with insulationlayer(B) current through supply line flows at slowerspeed.(C) supply wires arc made of superior material(D) resistance of heater coil is more than thatsupply wires.

101. The resistance of 1 meter length of 18gauge copper wire is k ohm. The resistance ofone metre length of 24 gauge copper wire willbe

(A) k / 2 ohm(B) 18 / 24 kohm(C) k ohm(D) more than k ohm.

102. In the circuit shown below, the resistance R hasa value that depends on the current Specially, R is 20ohms when the current I is zero, and the amount ofincrease in resistance is numerically equal to onehalfthe current. What is the value of the current in thecircuit?

116. For the circuit shown in the figuregiven below, the meter will read

(A) 1 A(B) 5 A(C) 10 A(D) 25 A117. For the circuit shown infigure given below, the reading in theammeter A w ill be

(A) 8.33 A(B) 10.0 A(C) 12.5 A(D) 50 A.103. If the length and diameter of aconductor is tripped, the resistance will increaseapproximately by

(A) 66 2/3 %(B) 33 1/3 %(C)66 2/3 %(D) 33 1/3 %.

104. If the resistance of an incandescent light bulbchanges as the voltage across the bulb is changed,which of the following is true ?

(A) The internal inductance of the bulb causes thischange(B) The bulb is said to have a low ionization potential(C) The bulb has constant resistance of the currentthrough the bulb is changed(D) The bulb is a type of nonlinear resistance.

105. Which method can be used for absolutemeasurement of resistance ?

(A) Ohm’s law method(B) Wheatstone bridge method(C) Raleigh method(D) Lortentz method.

106. Two 1 kilo ohm, 1/2 W resistors are connected inseries. Their combined resistance value and wattagewill be

(A) 2 kohm, 1 / 2 W(B) 2 kohm, 1 W(C) 2kohm, 2 W(D) 1 kohm, 1 / 2 W.

107. The resistance of 100 W, 200 V tamp is

108. A cylindrical wire is compressed in length by10%. The percentage decrease in the resistance willbe

(A) 16%(B) 19%(C) 20%(D) 25%.

(A) 2 A(B) 0.5 A(C) 0.4 A(D) 0.2 A.118. According to Joule lawheat produced by a current I while inflowing through a material of resistance Rfor a length of time T, is proportional to

(A) T only(B) (RT)(C) (IRT)(D) (I2RT).

119. In the color code for resistancesblack color represents the number (A) 0

(B) 1(C) 2(D) 3.

120. In the color code white colorrepresents the number

(A) 9(B) 8(C) 6(D) 5.

121. In the color code number 3 isrepresented by

(A) blue(B) orange(C) grey(D) violet.

122. The condition for the validity underOhm’s law is

(A) Temperature at positive end shouldbe more than the temperature at negativeend(B) Current should be proportional to thesize of resistance(C) Resistance must be wire wound type(D) Resistance must be uniform.

123. In which figure the relationship

109. Three resistance of 6 ohm each are connectedas shown in Figure given below. The equivalentresistance between X1 and X2 is

(A) 2 ohm(B) 4 ohm(C) 8 ohm(D) 12 ohm.110. The unit of conductance is

(A) per ohm(B) ohm/m(C) mho/m(D) mho.

111. Ohm’s law is not applicable in all the followingcases except

(A) Electrolysis(B) Arc lamps(C) Insulators(D) Vacuum radio valves.

112. In which of the following circuits will the voltagesource produce the most current?

(A) 10 V across a 10 ohm resistance(B) 10 V across two 10 ohm resistance in series(C) 10 V across two 10 ohm resistances in parallel(D) 1000 V across Mohm resistance.

113. A piece of sliver wire has a resistance of 1 ohm.A manganin wire has specific resistance 30 times thatof silver. The resistance of a manganin wire of onefourth length and one third diameter will be

(A) 6 / 5 ohm(B) 1 ohm(C) 67.5 ohm(D) 86.75 ohm.

114. A cube of material of side 1 cm has a resistanceof 0.002 ohm between its opposite faces. If the samevolume of the material has a length of 8 cm and auniform crosssection, the resistance of this length will be

between voltage V and current I is inaccordance with Ohm’s law ?

(A) Figure A(B) Figure B(C) Figure C(D) Figure D.124. Production of heat dueto current is related by which law

(A) Ohm’s law(B) Joule’s law(C) Kelvin’s law(D) Maxwell’s law.

125. A fixed resistance R is connectedacross a DC voltage source. If thevoltage is gradually and uniformlyincreased, the relationship betweenvoltage and resistance is correctlyrepresented in which group?

115. The unit of conductivity is

(A) mho / m(B) mho / sq. m(C) ohm / m(D) ohm / sq. m.

(A) Group A(B) Group B(C) Group C(D) Group D.126. The maximum powerthat can be distributed in the load in thecircuit shown in

(A) 3 watts(B) 6 warts(C) 6.75 watts(D) 13.5 watts.

127. A variable resistance R is connected across asource of voltage V. If the value of the resistance Ris gradually varied, the relationship between I and Rwill be represented by which curve ?

(A) Figure A(B) Figure B(C) Figure C(D) Figure D.128. A 1 k, 1 W resistor can safely passa current of

(A) 30mA(B) 100mA(C) 150 mA(D) 500 mA.

129. The resistance to the flow of current through acopper wire

(A) increases as the length of wire decrease(B) decreases as the diameter of wire decreases

165. For a carboncomposition resistorcolorcoded with yellow, violet, orangeand silver stripes from left to right, thevalue of resistance and tolerance are(A)470 ohm ± 10%(B) 47ohm ± 10%(C) 740 ohm ± 50%(D) 74 ohm ± 5%.

166. For a carboncomposition resistorcolor coded with green, black, gold andsilver stripes from left to right, theresistance and tolerance are

(A) 50 ohm ± 10%(B) 5 ohm ± 5%(C) 5 ohm ± 10%(D) 0.5 ohm ± 5%.

167. A resistor with the color coded valueof 1000 ohms and ± 10% tolerance canhave an actual resistance between

(A) 990 ohm and 1010 ohm(B)900 ohm and 1100 ohm(C)1000 ohm and 1100 ohm(D)900 ohm and 1000 ohm.

168. For carbon resistors what is the colorfor 5?

(A) Green(B) Black(C) Orange

(C) increases as the length of wire increases(D) decreases as the length of wire increases.

130. For the same voltage, the ratio Resistance of100 W lamp Resistance of 25 W lamp is:

(A) 1(B) 4(C)16(D)1 / 4.

131. The voltage drop across a resistor of 100 ohmis 10 volts. The wattage of the resistor must be

(A) 1 / 2 W(B) 1 W(C) 2 W(D) 4 W.

132. A 100 volt bulb has a resistance of 500 ohms.The number of hours it can work for every kWh ofenergy consumed will be

(A) 20(B) 40(C) 50(D) 60.

133. A semiconductor is

(A) one which conducts only half of applied voltage(B) a material whose conductivity is same asbetween that of a conductor and an insulator(C) a material made of alternate layers of conductingmaterial and insulator(D) a material which has conductivity a havingaverage value of conductivity of metal and insulator.

134. Two resistors R1 = 47 kohm, 1 W and R2 = 0ohm, 1 W are connected in parallel. The combinedvalue will be

(A) 47 kohm, 1 W(B) 47 kohm, 2W(C) 47 kohm, 1 / 2 W(D) 0 kohm, 1W.

135. A rheostat differs from potentiometer in therespect that

(A) rheostat has large number of turns(B) rheostat offers larger number of tappings(C) rheostat has lower wattage rating(D) rheostat has higher wattage ratings.

136. The equivalent resistance at the points X1 and

(D) Gray.

169. For carbon resistors, darker colourgenerally have values close to (A) 1

(B) 5(C) 8(D) 9.

170. In a carbon resistor in case fourthstripe is not present, it can be concludedthat

(A) the resistor is highly accurate(B) the resistor is defective(C) the resistor does not contain carbon(D) the tolerance limit is ± 20 %.

171. The four stripes of a resistor areyellowvioletorangegold. The value ofresistor should be

(A) 470 ohms ± 5 %(B) 47 kilo ohm ± 5%(C) 47 mega ohms ± 5%(D) 4700 ohms ± 10%.

172. The tolerance for silver stripe is

(A)+5%(B)+ 10%(C)± 5%(D)± 10%.

173. Which of the following can havepositive or negative charge?

(A) Electron(B) iron(C) Hole(D) Neutron.

174. Which of the following parallelresistances will have the highest value ofequivalent resistance?

(A) 10 kohm and 25 kohm(B) 1 kohm, 2 kohm and 3 kohm(C) Two 500 kohm resistors(D) Four 40 kohm and two 10 kohmresistors.

175. In series as well as parallel circuitsthe equivalent (total) value of certainparameter is given by X = X1 + X2 + X3 +X4 + … The parameter X could be

X2 in the circuit shown below

(A) 60 ohm(B) 40ohm(C) 80 ohm(D) 20ohm.137. For the same electrical resistance,the weight of aluminium conductor as compared tocopper conductor of identical crosssection is (A)85%

(B) 50%(C) 20%(D) 120%.

138. A drawn wire of resistance 25 ohm is furtherdrawn so that its diameter becomes one fifth. Itsresistance will now be

139. Which of the following has negative coefficientof resistance?

(A) Wire wound resistor(B) Metals(C) Nonmetals(D) Thermistor.

140. The current at a given point in a certain circuitmay be written as a function of time t, as i ( t ) = 3 +t. The total charge passing a point between t = 99and t = 102 sec will be

(A) 112 coulombs(B) 242.5 coulombs(C) 292.5 coulombs(D) 345.6 coulombs.

Questions 141 and 142 refer to the data givenbelow:

A certain passive circuit element has thecharacteristic that the instantaneous voltage across itis always exactly three times the cube of theinstantaneous current through it

(A) resistance(B) current(C) voltage(D) power.

176. The resistance of a 150scalevoltmeter is 12000 ohms. The powerconsumed by the voltmeter when it isconnected across a 125 volt circuit, will benearly

(A) 0.0013 W(B) 0.013 W(C) 0.13 W(D) 1.3 W.

177. Materials having electricalconductivity much less than most of themetals but much greater than that oftypical insulators, are known as

(A) thermistors(B) varistors(C) semiconductors(D) variable resistors.

178. Match the following :

Column 1 Column 2Copper ResistorsSalt SolutionElectrolytic ConductorGermanium GoodConductor FerronickelalloysSemi Conductors

(A) a(i), b(ii), c(iii), d(iv)(B) a(ii), b(iii), c(iv), d(i)(C) a(iiii),b(i), c(ii), d(i)(D) a(iii), b(ii) c(iv), d(i).

179. In the circuit shown below, thecurrent I is

141. The power being dissipated when i = 0.1 A willbe

(A) 3 W(B) 0.3 W(C) 3 x 103 W(D) 3 x 10 4 W.

142. The power being dissipated when i = 10 A willbe

(A) 3 W(B) 30 W(C) 3 kW(D) 30 kW.

143. A resistor has the value of 30 kohm and thecurrent in it is measured to be 0.5 mA. Theconductance is

(A) 15(B) 30000(C) 3.33 x 105(D) 3.33 x 103

144. In the above problem, the terminal voltage mustbe

(A) 15 mV(B) 1.5 V(C) 15 V(D) 150 V.

145. The charge of an electron is known to be 1.6 x1019C. How many electron does not 1 make it C ofcharge ?

(A) one(B) one million(C) 6.2 x 1018(D) 1.6 x 1019.

146. The current entering the terminal of an elementis given by the equation i ( t ) = 106 t2 – 107t A. Thetotal charge flowing, into the element between t = 1 sand t = 2 s will be nearly

(A) 2.2 x 106C(B) 1.6 x 10 6C(C) 0.6 x 108C(D) 0.6 x 10 10C.

147. An electron in a vacuum tube is observed tolose 1.6 x 1020 J of energy in moving from point Ato point B. The voltage of point B with respect ofpoint A is

(A)1 / 45 A(B)1 / 15 A(C)1 / 10 A(D)1 / 5 A.180. In a nickelcadmiumalkalicell the electrolyte is

(A) sulphur acid(B) potassium hydroxide(C) zinc chloride(D) ammonium chloride.

(A) 19.5 ohms(B) 14.5 ohms(C) 9.75 ohms(D) 5.55 ohms.182. There are 8.5 x1028 free electrons in one cubic metre ofcopper. When the copper conductor isworked at 155 A/cm2 the velocity of theaxial drift will be

(A) 1.14 x 106 m/s(B) 1.14 x 105 m/s(C) 1.14 x 104 m/s(D) 1.14 x 103 m/s.

183. Two batteries have an opencircuitvoltage of 12.8 volts each and an internalresistance of 0.08 ohms. The short circuitcurrent of two batteries connected inparallel will be

(A) – 1 V(B) + 1 V(C) 0.1V(D) + 0.1 V.

148. In electronic microcircuits, a resistor may befabricated from a constantthickness layer of semiconductor material with conductor connections at theedges as shown in Figure given below. If the resistorshown has resistance R, then a similar resistor 0.2millimeter by 0.2 millimeter has a resistance of

(A) 4 R(B) 2 R(C) R(D) R / 2149. Certain substances lose their electricalresistance completely at finite low temperatures.Such substances are called

(A) dielectrics(B) superconductors(C) semi conductors(D) perfect conductors.

150. We have three resistances each of 1 ohm. Howmany different values of resistance can be obtainedby different seriesparallel combinations if all thethree resistances are to remain in the circuit?

(A) Three(B) Four(C) Five(D) Six.

151. A resistor has the value of 3 kohm and thecurrent through it is measured to be 0.3 mA. Theconductance is

(A) 30000 mho(B) 30 mho(C) 0.33 milli mho(D) 30 micro mho.

152. Resistance between X1 and X2 is

(A) 80 A(B) 120 A(C) 160 A(D) 320 A.

Questions 184 and 185 refer to datagiven below:

A radiator element supplied at 240 Vdissipates 2.4 MJ in 20 minutes.

184.The power dissipated in the elementsis

(A) 2000 W(B) 1000 W(C) 500 W(D) 200 W.

185.The resistance of the element is

(A) 68 ohms(B) 28.8 ohms(C) 14.4 ohms(D) 7.2 ohms.

Questions 186 to 188 refer to datagiven below :

Two loads X and Y, are connected inparallel to a 115 V supply. Load X takes35 watts and the total current is 2.6 A.

186.The resistance of X is

187.The resistance of Y is

188.The power absorbed by Y is

(A) 528 W(B) 264 W(C) 132 W(D) 66 W.

Questions 189 and 190 refer to datagiven below:

A source whose noload voltage is 220 V

(A) 10 ohm(B) greater than 10 ohm(C) 0(D) less than 10 ohm.153. When checked with anohm meter an open resistor reads

(A) zero(B) high but within tolerance(C) low but not zero(D) infinite.

154. A current of 1 mA flows through a 1 Mohm, 2 Wcarbon resistor. The power dissipated as heat in theresistor will be

(A) 2 W(B) 1 W(C) 0.5W(D) 0.1W.

155. Which of the following carbon coded resistorhas value of 10 kohm with 20% tolerance?

(A) Red, red, green and silver stripes(B) Yellow, violet, yellow and silver stripes(C) Orange, orange, black and gold stripes(D) Brown, black, orange and no tolerance band.

156. A carbon resistor has to meet the followingrequirements IR drop: 5 V, Current: 100 mA, Safetyfactor for power dissipation : 2. Which of thefollowing resistors will be suitable ?

(A) 5 ohm, 10 W(B) 0.5 ohm, 100 W(C) 5 ohm, 10 W(D) 50 ohm, 1 W.

157. A 10 ohm resistor with a 10 W power rating isexpected to be a

(A) carbon resistor(B) wire wound resistor(C) either carbon or wire wound resistor(D) neither carbon nor wire wound resistor.

158. Two 10 kohm, 5 W resistors in parallel haveequivalent resistances of 5 kohm and power rating of

(A) 2.5 W

delivers 20 watts to a load when thecurrent is 0.4 A.

189. The internal resistance of the sourceis

190.The maximum power that can bedelivered by the source is

(A) 51 W(B) 102 W(C) 152 W(D) 242 W.

191. All good conductors have high

(A) resistance(B) electrical conductivity(C) electrical and thermal conductivity(D) conductance.

192. A light dependent resistor is basicallya

(A) power resistor(B) nonmetallic resistor(C) carbon resistor(D) variable resistor.

193. Voltage dependent resistors areusually made from

(A) graphite(B) charcoal(C) silicon carbide(D) nichrome.

194. The power rating of a 470 ohmresistor carrying a current of 40 mAshould be

(A)1 / 4 W(B)1 / 2 W(C) 1 W(D) 2 W.

195. Resistance across A and B in thecircuit shown below is

(B) 5 W(C) 10 W(D) 25 W.

159. Which of the following is typical resistance andpower dissipation value for a wire wound resistor?

(A) 1Mohm, 1 / 3 W(B) 50kohm, 1 / 2 W(C) 500 ohm, 1 W(D) 10 ohm, 50 W.

160. A 100 kohm resistor with a 1 W power rating islikely to be a

(A) carbon resistor(B) wire wound resistor(C) either carbon or wire wound resistor(D) neither carbon nor wire wound resistor.

161. Two 5 kohm, 5 W resistors in series haveequivalent resistance of 10 kohm with power ratingof

(A) 2.5 W(B) 5 W(C)10W(D) 25 W.

162. Which of the following are typical resistanceand powerdissipation values for a carboncomposition resistor ?

(A) 10,000 ohm, 10 W(B) 1000,000 ohm, 1 W(C) 5000 ohm, 100 W(D) 10 ohm, 50 W.

163. A resistor is to be connected across a 45 Vbattery to provide 1 mA of current. The requiredresistance with a suitable wattage rating is

(A) 45 ohm, 10 W(B) 4.5 ohm, 2 W(C) 450 kohm, 2 W(D) 45 kohm, 1/4 W.

164. In the circuit shown below, heat produced in 5ohm resistance is 10 cal/sec. Heat developed in4ohm is

Picture

(A) 1 cal/sec(B) 2 cal/sec(C) 3 cal/sec

(A) R(B) 3 R(C) 4 R(D) 5 R.196. Voltage dependent resistorsare used

(A) as current stabilizers(B) as heating elements(C) for inductive circuits(D) to suppress surges.

197. Metals approach superconductivityconditions

(A) near absolute zero temperature(B) near critical temperature(C) at triple point(D) under the conditions of hightemperature and pressure.

198. In which of the following theresistance decreases with rise intemperature ?

(A) LDR(B) NTC thermistors(C) Nichrome conductors(D) ACSR conductors.

199. The equivalent resistance of 2Nbranches in parallel, each havingresistance N/2 ohms will be

(A) 4 ohms(B) 2 ohms(C) 1 ohm(D) 1 / 4 ohm.

200. Equivalent Resistance between Xand Y is

(D) 4 cal/sec.

(A)50 ohm(B) 75 ohm(C)275 ohm(D)none of the above.

Answers:1.B —– 2.D —– 3.B —– 4.B —– 5.D —– 6.C —– 7.C —– 8.B —–9.D —–10.B —–11.C —– 12.C —–13.A —–14.B —– 15.C——16.D —–17.B —– 18.D —– 19.C —– 20.B —– 21.C —– 22.A —– 23.A —–24.B —–25.C —–26.A —– 27.D —–28.A —–29.C —– 30.B—31.B —– 32.C —– 33.D —– 34.B —– 35.D —– 36.D —– 37.C —– 38.B —–39.D —–40.A —–41.C —– 42.D—–43.C —–44.C —– 45.C——46.D —–47. B —– 48.A —– 49. D —– 50. B —– 51.D —– 52. C —– 53. B —– 54.C —– 55. D—– 56. A —– 57. D —– 58. C —– 59. C —– 60. A—–61.A —– 62. B —– 63. A —– 64. C —– 65. D —– 66. A —– 67. C —– 68.C —– 69. D —– 70. C —– 71. A —– 72. C —– 73. D —– 74. A —– 75.D—76.C —– 77.B —– 78.C —– 79.D —– 80.B —– 81.D—– 82.C —– 83. A —–84.B —– 85.B —– 86.C —– 87.D —– 88.B —– 89.B —– 90.D—91.A —– 92.A —– 93. A—– 94.B —–95.C —– 96.A —–97.D —– 98.C —–99.B —– 100.D —– 101.D —– 102.B —– 103.C —– 104.D —–105.B—106.B —–107.C—– 108.B —– 109.A —– 110.D —– 111.C —– 112.C —–113.C —– 114.D —– 115.A —– 116. C —–117.C —– 118.D —–119.A —–120.A—121.B —–122.D —– 123.B —– 124.B —– 125.A —– 126.C —–127.B —–128.A —– 129.C —– 130.D —–131.B —– 132.C —– 133.B —–134.D —–135.D—136.B —– 137.B —– 138.A —– 139.D —– 140.C —– 141.D —– 142.D —–143.C —– 144.C —– 145.C —– 146.A —– 147.C —– 148.C —– 149.B —– 150.B—151. C —–152.C —–153.D —–154.B —–155.D —– 156.D —– 157.B —– 158.C —– 159.D —–160.A —–161.C —– 162.B —– 163. D—– 164.B —– 165.B—–166. C—–167.B —–168.A —–169.A —– 170.D —– 171.B —– 172.D —– 173.B —– 174.C —–175.D —–176.D —– 177.C —– 178. D—– 179.C —– 180.B—181. C —–182.C —–183.D —–184.A —– 185.B —– 186.A —– 187.C —– 188.B —– 189.C —–190.D—–191.D —– 192.D —– 193. C—– 194.C —– 195.A —– 196.D —– 197.A —– 198.B —– 199.D —– 200.D

short notes _ eee press.pdf

Documents

wgv aktuell sammelmappe · sss uuu ccc hhh eee nnn www iii...

racism and press.pdf

race, riots and the press.pdf

hindi book-kalyan-yogank by gita press.pdf

hindi book-bhakti ank by geeta press.pdf

hindi book-nari ank by gita press.pdf

eee pc hardware manual eee pc 1000 series eee pc 904 series

eee- 601 power system analysis...

totaka with tika 1888 - jagadeeshwar printing press.pdf

hindi book-kalyan by gita press.pdf

eere identity and design guidelines for communications ·...

hindi book-keno upnishad by gita press.pdf

national enginnering collegenec.edu.in/pdf/eee/newsletter/13...

generel zelene mesta banskÁ bystrica · 2019-09-04 · e...

eee...eee ... eee

770 digital colour press.pdf

rr eee fff ooo rrr m mm aaa sss ppp rrr eee sss eee … ·...

bocksöpen - portawestfalica.de · jjj jjj jjj jjj jjj jjj...

uuu nnnsss eee eee nnn:: - txcsotconference.com

emec1(eee-451) ivsem eee