set 8 MCQ Questions & Answers Detailed Explanation

Question : 1

The device used for converting alternating current to direct current is called

a) Transformer

b) Inverter

c) Rectifier

d) Transmitter

Question : 2

The part of the transistor which is heavily doped to produce large number of majority carriers is

a) base

b) collector

c) emitter

d) any of the above depending upon the nature of transistor

Question : 3

Which of the following is the most suitable material for making permanent magnet ?

a) Copper

b) Steel

c) Soft iron

d) Nickel

Question : 4

Some pairs of devices and associated energy changes are given below.

1. Electric generator - Mechanical to electrical
2. Electric motor - Electrical to mechanical
3. Diesel engine - Light to electrical
4. Solar cell - Chemical to mechanical

a) 2 and 4

b) 1 and 2

c) 1 and 3

d) 3 and 4

Question : 5

The ratio of the focal length of the objective to the focal length of the eyepiece is greater than one for

a) both microscope and telescope

b) a microscope

c) a telescope

d) neither microscope nor telescope

Question : 6

In charging a battery of motor car, the following effect of electric current is used

a) heating

b) chemical

c) magnetic

d) induction