Question

Two identical circular coils $A$ and $B$ are kept on a horizontal tube side by side without touching each other. If the current in the coil $A$ increases with time, in response, the coil $B$

• A. is attracted by $A$
• B. remains stationary
• C. is repelled
• D. rotates

Answer 1

Answer: (C)

is repelled

Answer 2

As the current in coil $A$ changes, the magnetic flux linked with coil $B$ changes, hence as a result current induces in coil $B$. The direction of induced current in coil $B$ is opposite to that of the direction of current in coil $A$ as shown in figure

Due to currents in opposite directions in the near by sides of the coil, the coil $B$ is repelled.