The magnetic field existing in a region is given by B=Bo(1+x/l)k cap.A square loop of edge length l carrying a current i, is placed with its edge parallel to the xy axes .Find the magnitude of the net magnetic force experienced by the loop.The answer given is Boil.In this problem why don`t we consider the y component of length while finding the net force???

Dear student,

Actually we are considering only the Y-components of length and not the X- components. This is so because the variation of magnetic field with X axis results in different forces exerted on the lengths along Y axis due to having a difference ofin the magnitude of magnetic field over them.

However for lengths along X-axis, the variation of magnetic field with X- axis is exaclty same with opposite directions of current flow. Hence the two forces will cancel each other.