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