set 7 MCQ Questions & Answers Detailed Explanation

Question : 1

What is the difference between a CFL and an LED Lamp?

1. To produce light, a CFL uses mercury vapour and phosphor while an LED lamp uses semiconductor material.
2. The average life span of a CFL is much longer than of an LED lamp.
3. A CFL is less energy efficient as compared to an LED lamp.

a) 1 and 3

b) Only 1

c) 2 and 3

d) 1, 2 and 3

Question : 2

A current I flows through a potential difference V in an electrical circuit containing a resistance R. The product of V and I, i.e., VI may be understood as

a) thermal power radiated by the circuit

b) resistance R

c) heat generated by the circuit

d) rate of change of resistance

Question : 3

Assertion (A):
In India, electricity distribution companies calculate the consumption of electricity in kWh.
Reason (R):
Electrical system in India works at a frequency of 60 Hz.
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a) (A) is true, but (R) is false

b) Both (A) and (R) are true and (R) is the correct explanation of (A)

c) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 4

Which one of the following is a non-magnetic substance?

a) Nickel

b) Iron

c) Cobalt

d) Brass

Question : 5

Which of the following sentences is/are correct about a conductor of electricity?

1. Metals in general are good conductors of electricity.
2. Distilled water conducts electricity.
3. Top water conducts electricity.
4. Rubber is a bad conductor of electricity

a) 1, 3 and 4

b) 1 and 2

c) 2 and 3

d) 1, 2 and 3

Question : 6

When a fuse is rated 8A, it means

a) it has a resistance of 8 ohm

b) it will work only if current is 8A

c) it will not work if current is less than 8A

d) it will burn if current exceeds 8A