A magnet NS is suspended from a spring and while it oscillates, the magnet moves in and out of the coil C. The coil is connected to A a galvanometer G. Then, as the magnet oscillates,

Options

A. G shows no deflection
B. G shows deflection to the left and right but the amplitude steadily decreases
C. G shows deflection to the left and right with constant amplitude
D. G shows deflection on one side.

Answer

B

Explanation

As the south pole approaches the coil the current flows clockwise lo cancel changes in the magnetic flux. Now the top of the coil is south pole. When the south pole moves up, the current flows anticlockwise lu produce a north pole in the coil to cancel the change of flux Flux varies and therefore amplitude will not be a constant.