Question

A wire of magnetic dipole moment M and L is bent into shape of semicircle of radius r. What will be its new dipole moment? 

A) M

B) M/2π

C) M/π

D) 2M/ π

Answer 1

The correct option is D) 2M/ π.

Let us consider a wire of length L and radius r. 

It is bent in a semicircular shape.

Hence Length of wire = circumference of semicircle

L= πr 

r = L/π 

Formula to be used Dipole moment = magnetic moment x minimum separation between two dipoles.