basic electrical MCQs – Page 4

Practise focused basic electrical questions with marked answers for exam preparation and subject revision.

basic electrical Mcqs

61. A closed switch has a resistance of_____________?
0

A. about 50 ohms

B. zero

C. about 500 ohms

D. infinity

62. Which quantity should be measured by the voltmeter ?
0

A. Current

B. Power

C. Speed

D. Voltage

63. The resistance of a copper wire 200 m long is 21 Q. If its thickness (diameter) is 0.44 mm, its specific resistance is around_______________?
0

A. 1.8 x 10?8 Q-m

B. 1.6 x 10?8 Q-m

C. 1.2 x 10~8 Q-m

D. 1.4 x 10~8 Q-m

64. Capacitor does not allow the sudden change of ?
0

A. None of the above

B. power

C. current

D. voltage

65. If a parallel circuit is opened in the main line, the current_______________?
0

A. is zero in all branches

B. increases in the branch of the lowest resistance

C. increases in each branch

D. is zero in the highest resistive branch

66. Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes__________?
0

A. 9 times

B. 1/9 times

C. unchanged

D. 3 times

67. When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will___________?
0

A. remain constant

B. none of the above

C. decrease

D. increase

68. Bulbs in street lighting are all connected in_____________?
0

A. series

B. parallel

C. series-parallel

D. end-to-end

69. are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators______________?
0

A. Thermistor

B. Variable resistors

C. Semi-conductors

D. Varistors

70. Switching of a lamp in house produces noise in the radio. This is because switching operation produces________?
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A. arcs across separating contacts

B. mechanical noise of high intensity

C. both mechanical noise and arc between contacts

D. none of the above

71. For testing appliances, the wattage of test lamp should be_____________?
0

A. any value

B. low

C. very low

D. high

72. Which of the following can have negative temperature coefficient _____________?
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A. Metallic alloys

B. Liquid metals

C. Compounds of silver

D. Electrolytes

73. A thermistor has_____________?
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A. zero temperature coefficient

B. positive temperature coefficient

C. negative temperature coefficient

D. variable temperature coefficient

74. Whether circuit may be AC. or D. C. one, following is most effective in reducing the magnitude of the current?
0

A. Capacitor

B. Resistor

C. Inductor

D. Reactor

75. When one leg of parallel circuit is opened out the total current will______________?
0

A. become zero

B. reduce

C. decrease

D. increase

76. A nichrome wire used as a heater coil has the resistance of 2 2/m. For a heater of 1 kW at 200 V, the length of wire required will be_____________?
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A. 60 m

B. 80 m

C. 40 m

D. 20 m

77. Voltage dependent resistors are used_____________?
0

A. for inductive circuits

B. to supress surges

C. as heating elements

D. as current stabilizers

78. 74. Sparking occurs when a load is switched off because the circuit has high_________?
0

A. inductance

B. resistance

C. capacitance

D. impedance

79. Resistance of a material always decreases if___________?
0

A. number of free electrons available become more

B. temperature of material is decreased

C. temperature of material is increased

D. none of the above is correct

80. Nichrome wire is an alloy of_____________?
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A. copper and silver

B. lead and zinc

C. nickel and chromium

D. chromium and vanadium

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