Two hollow, concentric, spherical shells are covered with charge (Figure 16-34). The inner sphere has a radius $R_{\mathrm{i}}$ and a surface charge density of $+\sigma_{i}$, while the outer sphere has a radius $R_{0}$ and a surface charge density of $-\sigma_{0}$. Derive an expression for the electric field in the following three radial
regions: (a) $\mathrm{r}<\mathrm{Ri}, r<R_{i}$, (b) $\mathrm{Ri}<\mathrm{r}<\mathrm{Ro}, R_{\mathrm{i}}<r<R_{\mathrm{o}}$, and (c) $\mathrm{r}>\mathrm{Ro}^{r}>R_{\mathrm{o}}$.
SSM Example $16-8$