Question

Potential difference across a capacitor of capacity $4\mu F$ is 1 kilovolt. The energy stored on capacitor is:

• A. $1J$
• B. $2J$
• C. $3J$
• D. $4J$

Answer 1

The correct option is B $2J$

Given that,

Capacity of capacitor $C=4\mu F$

Voltage $V=1kV$

We know that,

Store energy is

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

$E=\frac{1}{2}\times 4\times {10}^{-6}\times 1\times 1\times {10}^6$

$E=2J$

Hence, the energy stored on capacitor is $2J$