The strength of the induced potential difference depends on the relative speed between the coil and the magnet.

The direction of the magnetic force acting on a current-carrying wire placed in a strong magnetic field can be determined by which rule?

$A$ coil of insulated wire is connected to a galvanometer. Explain what happens if a bar magnet with its north pole towards one face of the coil is:
$(i)$ moved quickly towards the coil,
$(ii)$ kept stationary inside the coil,and
$(iii)$ moved quickly away from the coil?

The diagram below shows a coil connected to a centre zero galvanometer $G$. The galvanometer shows a deflection to the right when the $N$ pole of a powerful magnet is moved to the right as shown.
$(i)$ Explain why the deflection occurs in the galvanometer.
$(ii)$ Does the direction of current in the coil appear clockwise or anticlockwise when viewed from end $A$?
$(iii)$ State the observation in $G$ when the coil is moved away from $N$.
$(iv)$ State the observation in $G$ when,both coil and the magnet,are moved to the right at the same speed.

$A$ fuse is a $.......$ wire.

Explain briefly different methods of producing induced electromotive force $(emf)$.