There are two coils `A` and `B` as shown in Figure. A current starts flowing in `B` as shown, when `A` is moved towards `B` and stops when `A` stops moving. The current in `A` is counterclockwise. `B` is kept stationary when `A` moves. We can infer that

Options

A. There is a constant current in the clockwise direction in A
B. There is a varying current in A
C. There is no current in A
D. There is a constant current in the counter clockwise direction in A

Answer

D

Explanation

When A stops moving the current in B becomes zero, it possible only if the current in A is constant. if the current in A would be variable, there must be an induced emf (current) in B even if A stops moving.