MCQ
Aspherical shell with an inner radius $'a'$ and an outer radius $'b' $ is made of conducting material. Apoint charge $+Q$ is placed at the centre of the spherical shell and a total charge $- q $ is placed on the shell.
Assume that the electrostatic potential is zero at an infinite distance from the spherical shell. The electrostatic potential at a distance $R$ $(a < R < b)$ from the centre of the shell is (where $K = $ $\frac{1}{{4\pi {\varepsilon _0}}}$)
- A$0$
- B$\frac{{KQ}}{a}$
- C$K\,\frac{{Q - q}}{R}$
- ✓$K\,\frac{{Q - q}}{b}$
