Same as problem `4` except the coil `A` is made to rotate about a vertical axis in the plane of the coil (Figure). No currents flows in `B` if `A` is at rest. The current in coil `A`, when the current in `B` (at `t = 0`) is counterclockwise and the coil `A` is as shown at this instant, `t = 0`, is

Options

A. constant current clockwise
B. varying current clockwise
C. varying current counterclockwise
D. constant current counterclockwise

Answer

A

Explanation

When currect in coil B (at t = 0) is counterclockwise, constant in A (at t = 0) must be clockwise. Therefore direction, as per Lenz's law. Choice (a) is correct.