Physics - EMI/AC Question with Solution | TestHub

When a conducting disc or wheel of radius $r$ rotates with constant angular velocity of $\omega$ about its axis in a uniform magnetic field perpendicular to its plane and parallel to its axis of rotation, then,
Induced emf is given by, $\mathrm{e}=\frac{1}{2}{\mathrm{B}\omega {\mathrm{r}}^2}^2$ Here, $B=0.1\mathrm{T},\omega =10\mathrm{rad}/\mathrm{s},\mathrm{r}=0.5\mathrm{m}$ Substituting these values in Eq. (i), we get $$\therefore \mathrm{e}=\frac{1}{2}\times 0.1\times 10\times (0.5{)}^2=\frac{1}{8}\mathrm{V}=0.125\mathrm{V}$$