$A$ parallel plate capacitor carries a charge $q$. The distance between the plates is doubled by the application of a force. The work done by the force is

Three plates $A, B, C$ each of area $50 \, cm^2$ have a separation of $3 \, mm$ between $A$ and $B$ and $3 \, mm$ between $B$ and $C$. The energy stored when the plates are fully charged is (as shown in the figure):

$A$ $12 \;pF$ capacitor is connected to a $50 \;V$ battery. How much electrostatic energy is stored in the capacitor?

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

$A$ parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and the area of each plate is $A$,the energy stored in the capacitor is:

Two capacitors $C_1$ and $C_2$ are connected in parallel to a battery. The charge-time graph is shown below for the two capacitors. The energy stored in them is $U_1$ and $U_2$,respectively. Which of the given statements is true?