Question

A coil made of insulated copper wire is connected to a galvanometer. What would happen in following cases?
i) A bar magnet is inserted and removed from the coil.
ii) A bar magnet is held stationary inside the coil.

• A. It will deflect in the first case but not in the second case.
• B. It will not deflect the first case but will deflect in the second case.
• C. It will show deflection in both the cases.
• D. It will not show any deflection in both the cases.

Answer 1

The correct option is A

It will deflect in the first case but not in the second case.

Whenever there is a change in the magnetic field linked with the coil, a current is induced. Due to this, the galvanometer connected to it shows deflection. Here in the first case, since the bar magnet is inserted and removed from the coil, a change in magnetic field occurs and hence induces an emf.
When the bar magnet is kept stationary, there is no change in the magnetic flux linked with the coil, hence no current is induced, so galvanometer shows no deflection.