Physics - Magnetism Question with Solution | TestHub

A disc of radius$\mathrm{R}$rotates with a constant angular velocity$\mathrm{\omega }$about its own axis. The surface charge density of this disc varies as$\mathrm{\sigma }={\mathrm{ar}}^2$where$\mathrm{r}$is the distance from the centre of the disc. Determine the magnetic field intensity at the centre of the disc.