# A $900 \;pF$ capacitor is charged by $100\; V$ battery. How much electrostatic energy is stored by the capacitor?
$\begin{array}{1 1} 4.5 \times 10^{-6}\;J \\ 4.5 \times 10^{-4}\;J \\ 3.5 \times 10^{-6}\;J \\ 4.5 \times 10^{-4}\;J \end{array}$