Assertion: A parallel plate capacitor is charged by connecting it across a battery. The battery is then disconnected and separation between the plates is decreased as a result of which the energy stored in the capacitor decreases.

Reason: Energy stored in the capacitor is equal to the work done in charging the capacitor.

A piece of cloud is having area $25\times {10}^6 {\mathrm{m}}^2$ and electric potential of $10^{5}$ $\mathrm{V}$. If the height of cloud is $0.75 \mathrm{km}$, the energy of electric field between earth and cloud will be,

A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will be