Question

a solid sphere of mass m and radius r which has a charge q uniformly over its volume. the sphere is rotated about its diameter with angular speed (w). the magnetic moment of sphere is

Answer 1

$$\begin{gathered} I=q/t \\ \omega =2\pi /t \\ t=\frac{2\pi }{\omega } \\ I=\frac{q\omega }{2\pi } \\ magneticmoment=I\times Area \\ m=\frac{q\omega }{2\pi }\times 4\pi r^2 \\ m=2q\omega r^2 \end{gathered}$$