Question

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

A. rotate about an axis parallel to the wire 

B. move towards the wire 

C. move away from the wire or towards right 

D. remains stationary

Answer 1

For the loop, using Lenz’s Law, the force on the part which is nearer, due to the current in the long wire is attraction and force on the part which is farther is repulsion. 

F (attraction) > F (repulsion) 

Hence loop moves towards the wire.