Question

A thin magnetised wire of length 10 cm has a magnetic moment of 0.4 A m${}^2$ is bent such that there is a gap of 2 cm between its ends. Then final magnetic moment is :

• A. 0.8 A m${}^2$
• B. 0.02 A m${}^2$
• C. 0.08 A m${}^2$
• D. 0.01 A m${}^2$

Answer 1

The correct option is C 0.08 A m${}^2$

Final magnetic moment $=m \times gap\ between\ its\ ends\$
$=\frac{\mu }{2l}\times 2cm$
$=\frac{0.4}{10}\times 2=0.08A{m}^2$