Question

A wire of length L metre carrying current I ampere is bent in the form of circle. Find its magnetic moment.

Answer 1

Dear Student,

$$\begin{gathered} \mathrm{L}=2\mathrm{\pi r} \\ \mathrm{or},\mathrm{r}=\frac{\mathrm{L}}{2\mathrm{\pi }} \\ \mathrm{Magnetic}\mathrm{moment},\mathrm{M}=\mathrm{IA} \\ \mathrm{M}=\mathrm{I}\times {\mathrm{\pi r}}^2 \\ \mathrm{M}=\mathrm{I\pi }{\left(\frac{\mathrm{L}}{2\mathrm{\pi }}\right)}^2 \\ \mathrm{M}=\frac{{\mathrm{IL}}^2}{4\mathrm{\pi }} \end{gathered}$$