Question

The coil $A$ is made to rotate about a vertical axis as shown in figure. No current flows in $B$ if A is at rest. The current in coil $A,$ when the current in $B$ $(att=0)$ is counterclockwise and the coil $A$ is as shown at this instant, $t=0,$ is

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

Answer 1

The correct option is B

constant current clockwise

The counterclockwise flow of the current in coil B is equivalent to north pole of magnet. When coil $A$ starts rotating at $t=0,$ the current in $A$ is constant along clockwise direction by Lenz’s law.

Final Answer: Option (a)