Question

Three concentric spheres are shown in figure. Find the potential on surface of shell $B$. Charge on $A$, $B$ and $C$ are $3Q,-2Q$ and $Q$ respectively.

• A. $\frac{3kQ}{5R}$
• B. $\frac{4kQ}{3R}$
• C. $\frac{3kQ}{4R}$
• D. $\frac{3kQ}{2R}$

Answer 1

The correct option is C $\frac{3kQ}{4R}$

The potential on the surface of shell $B$ is given by,
$V_B=\frac{k3Q}{2R}+\frac{-k2Q}{2R}+\frac{kQ}{4R}=\frac{3kQ}{4R}$