Question

Eight charges having the value as shown in fig are arranged symmetrically on a circle of radium $0.4m$ in air. Potential at center ${}^{\prime }{O}^{\prime }$ will be

• A. $6.075\times {10}^{5}V$
• B. $252\times {10}^{4}V$
• C. $252\times {10}^{6}V$
• D. $zero$

Answer 1

The correct option is A $6.075\times {10}^{5}V$

Total potential at the centre $O$ of the circle is given by$,$

$V=\frac{1}{4\pi {\in }_0}\frac{q_{net}}{r}$

$V=\frac{1}{4\pi {\in }_0}\times \frac{1}{0.4}\times {10}^{-6}\left(5-7+15+7+10-5+3-1\right)$

$V=\frac{9\times {10}^9\times {10}^{-6}\times 27}{0.4}Volt$

$=6.075\times {10}^{5}V$

Hence,

option $\left(A\right)$ is correct answer.