Question

The energy stored in a capacitor of capacitance $C$ having a charge $Q$ under a potential $V$ is

• A. $\frac{1}{2}{Q}^{2}V$
• B. $\frac{1}{2}{C}^{2}V$
• C. $\frac{1}{2}\frac{Q^2}{V}$
• D. $\frac{1}{2}QV$
• E. $\frac{1}{2}CV$

Answer 1

The correct option is D $\frac{1}{2}QV$

$E=\frac{1}{2}C{V}^2\times \frac{C}{C}$

$Q=CV$

$\Rightarrow E=\frac{1}{2}\frac{Q^2}{C}$

$\Rightarrow E=\frac{1}{2}QV$