electric current and magnetism - Category wise Question and Answer Practice Test with Solutions

Question : 16

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

a) ferromagnetics

b) diamagnetics

c) paramagnetics

d) antimagnetics

Question : 17

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 : 18

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 : 19

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 : 20 [PCS (Pre) 2015]

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