Question

Two circular coils $A$ and $B$ are facing each other as shown in the diagram. The current $i$ through $A$ can be altered, then

• A. there will be repulsion between $A$ and $B$ if $i$ is increased
• B. there will be attraction between $A$ and $B$ if $i$ is increased
• C. There will be neither attraction nor repulsion when $i$ is changed
• D. Attraction or repulsion between $A$ and $B$ depends on the direction of current. It does not depend whether the current is increased or decreased

Answer 1

Answer: (A)

When current is increased in $A$ , magnetic flux passing through $B$ will increase, according to Lenz's law direction of induced current in $B$ will be such as there is repulsion between $A$ and $B$ .