Question

Electrostatic energy of $3.5\times {10}^{-4}J$ is stored in a capacitor at $700V$. What is the charge on the capacitor ?

Answer 1

Given : $u=3.5\times {10}^{-4}J$, $V=700V$
$u=\frac{1}{2}QV$
$Q=\frac{2u}{V}$
$=\frac{2\times 3.5\times {10}^{-4}}{700}$
$Q={10}^{-6}C$