basic electrical MCQs – Page 5

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

basic electrical Mcqs
81. Conductance : mho :: ____________?
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A. capacitance : henry

B. inductance : farad

C. resistance : ohm

D. lumen : steradian

82. A glass rod when rubbed with silk cloth is charged because__________?
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A. it takes in proton

B. it gives away positive charge

C. its atoms are removed

D. it gives away electrons
83. International ohm is defined in terms of the resistance of________________?
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A. the unit length of wire

B. a cube of copper

C. a cube of carbon

D. a column of mercury
84. Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct ?
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A. 100 W lamp will glow brighter

B. 40 W lamp will glow brighter

C. Both lamps will glow equally bright

D. 40 W lamp will fuse

85. A field of force can exist only between_____________?
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A. two metal particles

B. two molecules

C. two atoms

D. two ions
86. The thickness of insulation provided on the conductor depends on_____________?
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A. the magnitude of voltage on the conductor

B. the magnitude of current flowing through it

C. both A. and (b)

D. none of the above

87. A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will__________
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A. increase

B. remain same

C. decrease

D. heater will burn out

88. In the case of direct current____________?
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A. magnitude and direction of current remains constant

B. magnitude and direction of current changes with time

C. magnitude of current remains constant

D. magnitude of current changes with time

89. Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?
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A. 160 ohms

B. 80 ohms

C. 20 ohms

D. 10 ohms
90. If/, R and t are the current, resistance and time respectively, then according to Joules law heat produced will be proportional to_______________?
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A. I2R2t

B. I2Rf

C. I2R2t*

D. I2Rt
91. Which of the following quantities remain the same in all parts of a series circuit ____________?
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A. Current

B. Voltage

C. Power

D. Resistance

92. Temperature co-efficient of resistance is expressed in terms of___________?
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A. ohms/C

B. mhos/ohmC

C. mhos/C

D. ohms/ohmC
93. The insulation on a current carrying conductor is provided__________?
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A. to prevent leakage of current

B. to prevent shock

C. both of above factors

D. none of above factors

94. It becomes more difficult to remove_________________?
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A. third electron from the orbit

B. any electron from the orbit

C. second electron from the orbit

D. first electron from the orbit

95. Ohms law is not applicable to__________?
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A. small resistors

B. D. C. circuits

C. semi-conductors

D. high currents

96. In a lamp load when more than one lamp are switched on the total resistance of the load_____________?
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A. remains same

B. increases

C. decreases

D. none of the above

97. A substance whose molecules consist of dissimilar atoms is called____________?
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A. compound

B. super-conducto

C. semi-conductor

D. insulator

98. Which of the following statement is correct_______________?
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A. A semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator

B. A semi-conductor is a material made of alternate layers of conducting material and insulator

C. A semi-conductor is a material which has conductivity having average value of conductivity of metal and insulator

D. A semi-conductor is one which conducts only half of the applied voltage

99. When electric current passes through a metallic conductor, its temperature rises. This is due to__________?
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A. mutual collisions between metal atoms

B. mutual collisions between conducting electrons

C. the release of conduction electrons from parent atoms

D. collisions between conduction electrons and atoms
100. When current flows through heater coil it glows but supply wiring does not glow because______________?
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A. current through supply line flows at slower speed

B. supply wires are made of superior material

C. resistance of heater coil is more than the supply wires

D. supply wiring is covered with insulation layer