Question

There is a uniformly charged non conducting solid sphere made of material of dielectric constant one. If electric potential at infinity be zero, then the potential at its surface is $V$. If we take electric potential at its surface to be zero, then the potential at the centre will be

• A. $\frac{3 V}{2}$
• B. $\frac{V}{2}$
• C. $V$
• D. Zero

Answer 1

Answer: (B)

$V_{\text {surface }}=V+V_{\infty}$
If $V_{\infty}=0, V_{\text {surface }}=V$
If $V_{\infty}=-V, V_{\text {surface }}=0$
$V_{\text {cen }}=\frac{3 V}{2}+V_{\infty}=\frac{3 V}{2}-V=\frac{V}{2}$