In a charged capacitor,the energy resides in:

Energy per unit volume for a capacitor having area $A$ and separation $d$ kept at potential difference $V$ is given by

$A$ parallel plate capacitor having plate area $A$ and separation $d$ is charged to a potential difference $V$. The charging battery is disconnected and the plates are pulled apart to four times the initial separation. The work required to increase the distance between the plates is ($\epsilon_0 =$ permittivity of free space).

$A$ parallel plate air capacitor having area of each plate $A$ and the distance between the plates $d$ has a uniform electric field $E$ in the space between the plates. The energy stored in the capacitor is ($\epsilon_0$ = permittivity of free space).

$A$ $4\ \mu F$ capacitor is charged to $400\ V$ and then connected to a $1\ k\Omega$ resistor. How much heat energy in $J$ is produced?

The charge $q$ on a capacitor varies with voltage $V$ as shown in the graph. The area of $\Delta OPM$ represents: