set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

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

a) ferromagnetics

b) diamagnetics

c) paramagnetics

d) antimagnetics

Question : 2

Alternating current cannot be measured by D.C. ammeter because

a) A.C. changes direction

b) A.C. cannot pass through D.C. ammeter

c) average value of current for complete cycle is zero

d) D.C. ammeter will get damaged

Question : 3

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 : 4

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

Question : 5

Curie temperature is the temperature above which

a) a ferromagnetic material becomes diamagnetic

b) a ferromagnetic material becomes paramagenetic

c) a paramagnetic material becomes diamagnetic

d) a paramagnetic m aterial becomes ferromagnetic

Question : 6

How does the white light produce in the tube?

a) To accelerate the atoms

b) To heat up the copper wire

c) To heat up the filament

d) To oscillate molecule