A steel wire of length `l` has a magnetic moment M. It is bent into L shape from middle. The new magnetic moment is

Options

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

Answer

A

Explanation

When the wire is bent into L shape, the effective distance between the poles `=sqrt(((l)/(2))^(2)+((l)/(2))^(2))=(l)/(sqrt(2))`
`M.=m xx (l)/(sqrt(2))=(M)/(sqrt(2))`