In the arrangement shown in figure, there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then:

Options

A. The deflection in the galvanometer remains zero throughout
B. There is a momentary deflection in the golvanometer but it dies out shortly and there is no effect when the key is removed.
C. There are momentary galvanometer deflections that die out shortly, the deflections are in the same diirection.
D. There are momentary galvanometer deflections that die out shortly, the deflections are in opposidte directions. Thus the galvanometer shows momentary deflections in opposite dierections.

Answer

D

Explanation

In the above arrangement, whenever and electric current through the first coil is changed. An emf is induced in the coil due to change in magnetic in magnetic field lines which pass through the nighbouring second coil
When key is inserted and removed, then the magnetic field lines passes through second soil increases and decreases in two cases respectively. Therefore, the direction of currect in two cases is in opposite directions. Thus the galvanometer shows momentary deflections in opposite directions.