The charge $q$ on a capacitor varies with voltage $V$ as shown in the figure. The area of the triangle $AOB$ is proportional to

An air-filled 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 ($\epsilon_{0} =$ permittivity of free space).

$A$ 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

What is energy density? Write its formula.

An uncharged capacitor is connected to a battery. While charging the capacitor,how much is the energy lost,from the energy supplied by the battery (in $\%$)?

The area of a cloud is $25 \times 10^6\ m^2$ and the electric potential is $10^5\ V$. If the height of the cloud is $0.75\ km$, then the energy stored between the cloud and the earth is.....$J$