Question

A condenser is charged to a potential difference of 200 volts as a result of which it gains charge of 0.1 coulomb. When it is charged then the energy released will be :

• A. 1 J
• B. 2 J
• C. 10 J
• D. 20 J

Answer 1

Answer: (C)

10 J

The expression of energy released is $U=\frac{1}{2}C{V}^2$
as $Q=CV$ thus, $U=\frac{1}{2}CV.V=\frac{1}{2}QV=\frac{1}{2}\times 0.1\times 200=10J$