Current Electricity mcq with answers

Current Electricity Questions and Answers 

Current Electricity

Current Electricity mcq with answers objective: Types of questions and answers in Current Electricity, Current Electricity, Current Electricity quiz questions, and answers. 

 

1. When current flows through heater coil it glows but supply wiring does not glow because

A) current through supply line flows at a slower speed
B) supply wiring is covered with insulation layer
C) resistance of heater coil is more than the supply wires
D) supply wires are made of superior material

ANSWER= (c) resistance of heater coil is more than the supply wires

 

2. The condition for the validity under Ohm’s law is that

A) resistance must be uniform
B) current should be proportional to the size of the resistance
C) resistance must be wire wound type
D) temperature at the positive end should be more than the temperature at the negative end

ANSWER= (A) resistance must be uniform

 

3. A rheostat differs from a potentiometer in the respect that it

A) has a lower wattage rating
B) has a higher wattage rating
C) has a large number of turns
D) offers a large number of tapping

ANSWER= (b) has higher wattage rating

 

4. The weight of an aluminum conductor as compared to a copper conductor of identical cross-section, for the same electrical resistance, is

A) 50%
B) 60%
C) 100%
D) 150%

ANSWER= (A)50%

 

5. An open resistor, when checked with an ohm-meter reads

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

ANSWER= (B)infinite

 

6. are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators.

A) Varistors
B) Thermistor
C) Semi-conductors
D) Variable resistors

ANSWER= (C)Semi-conductors

 

7. All good conductors have high

A)conductance
B) resistance
C) reluctance
D) thermal conductivity

ANSWER= (A)conductance

 

8. Voltage dependent resistors are usually made from

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

ANSWER= (C)nichrome

 

9. Voltage dependent resistors are used

A) for inductive circuits
B) to supress surges
C) as heating elements
D) as current stabilizers

ANSWER= (B)to supress surges

 

10. The ratio of mass of proton to that of electron is nearly ?

A) 1840
B) 1841
C) 30
D) 20

ANSWER= (A) 1840

 

11. The number of electrons in the outer most orbit of carbon atom is ?

A) 3
B) 4
C) 6
D) 7

ANSWER= (B)4

 

12. With three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals the system?

A) 10 W
B) 20 W
C) 40 W
D) 60 W

ANSWER= (D) 60 W .

 

13. A thermistor has

A) positive temperature coefficient
B) negative temperature coefficient
C) zero temperature coefficient
D) variable temperature coefficient

ANSWER= (C)zero temperature coefficient

 

14. If/, R and t are the current, resistance, and time respectively, then according to Joule’s law heat produced will be proportional to

A) I2Rt
B) I2Rf
C) I2R2t
D) I2R2t*

ANSWER= (A) I2Rt

 

15. Nichrome wire is an alloy of

A) lead and zinc
B) chromium and vanadium
C) nickel and chromium
D) copper and silver

ANSWER= (C)nickel and chromium