A current i is flowing in a conductor of length l. When it is bent in the form of a loop then its magnetic moment will be-
Answer & explanation
Correct answer: option 1
$ M = IA = I\pi r^2$
$ 2\pi r = l $
$\Rightarrow M = I \pi \frac{l^2}{4\pi^2} = \frac{Il^2}{4\pi}$