A steel wire of length l has a magnetic moment M. It is bent into a semicircular arc. What is the new magnetic moment?

Options

A. `(M)/(2)`
B. `(M)/(sqrt(2))`
C. M
D. 2M

Answer

B

Explanation

M=ml and
`M=sqrt((Ml)/(2)^(2)+((ml)/(2))^(2))=(ml)/(sqrt(2))=(M)/(sqrt(2))`