Question

The wire of length L is bent in the form of square and circle.The ratio of their magnetic moment at their centre is
A. `pi//4`
B. `pi//6`
C. `pi//2`
D. `pi`

Answer 1

Correct Answer - A
`M oo A`
`therefore (M_(s))/(M_(c))=(pir^(2))/(l^(2))=(pi(L/(2pi))^(2))/((L)/(4))^(2)=(pi)/(4)`