Question

The electric potential at the centre of a hemisphere of radius R and having surface charge density $\sigma$ is

• A. $\frac{\sigma }{2{\epsilon }_0}$
• B. $\frac{\sigma }{{\epsilon }_0}$
• C. $\frac{\sigma }{{\epsilon }_0}R$
• D. $\frac{\sigma }{2{\epsilon }_0}R$

Answer 1

Answer: (D)

$V=\frac{1}{4\pi {\epsilon }_0}\frac{Q}{R}=\frac{1}{4\pi {\epsilon }_0}\frac{(4\pi R^2\sigma /2)}{R}=\frac{R\sigma }{2{\epsilon }_0}$