If the potential of a capacitor having capacity of `6 muF` is increased from 10 V to 20 V,then increase in its energy will be

Options

A. `2 xx 10^(-4)J`
B. `4 xx 10^(-4)J`
C. `3 xx 10^(-4)J`
D. `9 xx 10^(-4)J`

Answer

D

Explanation

Increase in energy `= U_(2) - U_(1) = (1)/(2)C(V_(2)^(2) - V_(1)^(2))`
`= (1)/(2) xx 6 xx 10^(-6)(20^(2) - 10^(2)) = 9 xx 10^(-4) J`