The diagram shows a coil of several turns of copper wire near a magnet NS. The coil is moved in the direction of arrow shown in the diagram.

(i) In what direction does the induced current flow in the coil?

(ii) Name the law used to arrive at the conclusion in part (i).

(iii) How would the current in coil be altered if:

1. the coil has twice the number of turns,
2. the coil was made to move three times fast?

(i) When north pole of the magnet is brought towards the end B of the solenoid, the induced current flows in the solenoid in direction A to B i.e., at the end B, the current is anticlockwise, so the end B of the solenoid becomes a north pole to repel the magnet. Thus it opposes the motion of north pole of the magnet towards the solenoid, which is the cause producing it.

(ii) The law used to arrive at the conclusion in part (i) is Lenz's law.

(iii) (a) Current is directly proportional to the number of turns. Hence, current becomes twice when the coil has twice the number of turns.

(b) The current in coil becomes thrice when the coil was made to move three times fast .