Question

The given figure shows a closed coil connected to a galvanometer G. The galvanometer shows a deflection to the right when N-pole of the bar magnet is brought closer to the coil AB.

(i) Why does the deflection occur in the galvanometer ?

(ii) State the observation when:

(a) the coil is moved away from N-pole

(b) both the coil and magnet are moved to the right with the same speed.

Answer 1

(i) As the magnet is moved closer to coil AB, the flux linked with the coil increases. This set up induced current in the coil as shown by deflection in the galvanometer. 

(ii) (a) The direction of induced current in the coil AB is reversed and the galvanometer shows a deflection to the left. 

(b) When both the magnet and the coil AB are moved towards the right with the same speed, the flux linked with the coil does not change. No induced current is set up. Hence no deflection is shown by the galvanometer.