With the help of a diagram, describe an experiment to show that a change in current flowing through a coil induces an electric current in a neighbouring coil.
Answer:
Take two different coils of insulated copper wire having large number of turns (50 or even more).Insert the coils over a non-conducting cylindrical thick paper roll as shown in figure. Connect a battery of 6 V, a plug key K in series of coil-1. With coil-2, connect a sensitive galvanometer. Now put the plug in key K. Galvanometer 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-1 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 neighouring coil is changing.