set 7 MCQ Questions & Answers Detailed Explanation

Question : 1

Kilowatt-hour is the unit of

a) electric power

b) electrical energy

c) potential difference

d) charge

Question : 2

Principle of fuse is

a) Heating effect of electricity

b) Chemical effect of electricity

c) Mechanical effect of electricity

d) Magnetic effect of electricity

Question : 3

An n-p-n transistor conducts when

a) both collector and emitter are positive with respect to the base

b) collector is positive and emitter is negative with respect to the base

c) both collector and emitter are negative with respect to the base

d) collector is positive and emitter is at same potential as the base

Question : 4

A device which converts chemical energy into electrical energy is called

a) Generator

b) Battery

c) Motor

d) Moving coil meter

Question : 5

The earth’s magnetic field is approximately

a) 10 Tesla⁴

b) 1 Tesla

c) 2 Gauss

d) 1 Gauss

Question : 6

An electric bulb of 100 watt is used for 4 hours. The unit of electric energy used is

a) 4

b) 400

c) 25

d) 0.4