Take two different coils of insulated copper wire having a large number of turns (50 or even more). Insert the coils over a non-conducting cylindrical thick paper roll as shown in the figure. Connect a battery of 6V, a plug key K in series of coil- 1. With coil-2, connect a sensitive galvanometer. Now put the plugin key K. Galvanorneter joined with coil-2 also gives a momentary deflection and then pointer quickly returns to its mean position. On removing plug from key K in coil-l, the needle momentarily moves but to the opposite side. It means that now the current flows in the opposite direction in coil 2. So we conclude that current is produced in coil-2 whenever the current flowing in the neighbouring coil is changing.
