Q. A rectangular loop carrying a current is situated near a long straight wire, such that the wire is parallel to one of he sides of the loop and is in the plane of the loop. If a steady current is established in the wire as shown in the diagram, the loop will Physics Question Image

 2174  238 AMUAMU 1997 Report Error

Solution:

: The horizontal sides of the rectangular loop will experience equal forces in opposite directions. There will be no resultant force on the loop due to these forces. Further force on the nearer vertical side of the loop will be greater than the force on farther vertical side of the loop. They are at different distance from the long vertical wire. The force on nearer side will be directed towards the long vertical wire and the force on the farther vertical side of loop will be towards right according to right hand rule. Therefore the loop will experience a net force of attraction towards the wire. The loop will therefore move towards the wire.