A metalic ring is dropped down, keeping its plane perpendicular to a constant and horizontal magnetic field. The ring enters the region of mangetic fied at `t=0` and completely emerges out `t= Ts`. The current in the ring varies as:

Options

A.
B.
C.
D.

Answer

B

Explanation

1. When the ring is just entering the magnetic field emf is induced and the current flows in one difection. 2. When the whole rings is surroundings the flux inside, there is no chaange in the flux.
Indiced emf = 0 current is zero.
3. When the ring just goes out of hte region of fludx, a pulse of current produced which is opposite to that of 1 given above.
b is the only figure that deescribes this.