Question

A current carrying circular loop of radius R is placed in the xy
plane with centre at the origin. Half of the loop with x > 0 is
now bent so that it now lies in the y-z plane.
(a) The magnitude of magnetic moment now diminishes
(b) The magnetic moment does not change
(c) The magnitude of B at (0, 0, z), z > R increases
(d) The magnitude of B at (0, 0, z), z >> R is unchanged

Answer 1

Answer:

For a circular loop of radius R carrying current, I placed in x−y plane, the magnetic moment M=IπR2. It acts perpendicular to the loop i.e., along with the z-direction. When half of the current loop is bent in y-z plane, the magnetic moment due to half current loop in x-y plane,M1=I(2πR2) acting along z-direction