A thin "bar" magnet of length `'l'` and magnetic moment `'M'` is bent at the mid point so that the two parts are at right angles. The new magnetic length and magnetic moment are respectively

Options

A. `(1)/sqrt(2),(M)/sqrt(2)`
B. `sqrt(2l),sqrt(2M)`
C. `(l)/sqrt(2),sqrt(M)`
D. `sqrt(2l),(M)/sqrt(2)`

Answer

A

Explanation

`M'=sqrt(M_(1)^(2)+M_(2)^(2))=sqrt(((M)/(2))^(2)+((M)/(2))^(2))=sqrt(2)(1)/(2)=(1)/sqrt(2)`