Physics - Capacitor Question with Solution | TestHub

The initial energy stored in the capacitor is given by:

$W=\frac{Q^2}{2C}$

When the charge is increased to $3Q$, the new energy stored in the capacitor becomes:

$W^{\prime }=\frac{(3Q{)}^2}{2C}$

$W^{\prime }=\frac{9Q^2}{2C}$

$W^{\prime }=9\left(\frac{Q^2}{2C}\right)$

$W^{\prime }=9W$

Answer: $9W$