Question

A flat coil ABCD Is freely suspended between the pole pieces of a U – shaped permanent magnet with the plane of coil parallel to the magnetic field. 

a) What happens when current is passed in the coil? 

b) When will the coil come to rest? 

c) Name the instrument which makes use of the principle stated above.

Answer 1

a) The coil will experience a torque due to which it will rotate. 

b) The coil will come to rest when its plane becomes normal to the magnetic field. 

c) DC motor.