Question

A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to the one of the sides of the loop and is in the plane of the loop. If a steady current I is established in wire as shown in figure, the loop will

Answer 1

Explanation:

The long straight wire and side AB carry current in the same direction, hence will attract each other.

The long straight wire and side CD carry current in the opposite direction, hence will repel each other.

Force on side BC will be equal and opposite to force on side DA.

Since CD is farther from the wire than AB, the force of attraction on AB will exceed the force of repulsion on CD.

Hence, there will be a net force of attraction on the loop ABCD and it will move towards the wire.