set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

The distance between two magnetic poles is doubled and their pole-strength is also doubled. The force between them

a) remains unchanged

b) increases to four times

c) decreases by half

d) increases to two times

Question : 2

Electroplating does not help in

a) shining appearance

b) metals to become hard

c) fine finish to the surface

d) protect metals against corrosion

Question : 3

If potential difference and current flowing through a wire is increased twice each, then electric power

a) Will increase two times

b) Will remain unaffected

c) Will increase four times

d) Will decrease half

Question : 4

Metals getting magnetised by orientation of atomic magnetic moments in external magnetic field are called

a) ferromagnetics

b) diamagnetics

c) paramagnetics

d) antimagnetics

Question : 5

At absolute zero, Si acts as

a) metal

b) insulator

c) non-metal

d) None of these

Question : 6

The core of a transformer is laminated because

a) ratio of voltage in primary and secondary may be increased

b) the weight of the transformer may be reduced

c) rusting of the core may be prevented

d) energy losses due to eddy currents may be minimised