The energy of a parallel plate capacitor when connected to a battery is $E$. With the battery still in connection,if the plates of the capacitor are separated so that the distance between them is twice the original distance,then the electrostatic energy becomes

If the potential difference across a capacitor is increased from $5 \,V$ to $15 \,V$, then the ratio of final energy to initial energy stored in the capacitor is

$A$ capacitor of capacitance $5 \mu F$ is charged by a battery of emf $10 \text{ V}$. At an instant of time,the potential difference across the capacitor is $4 \text{ V}$ and the time rate of change of potential difference across the capacitor is $0.6 \text{ Vs}^{-1}$. Then,the time rate at which energy is stored in the capacitor at that instant is:

$A$ $700\,pF$ capacitor is charged by a $50\,V$ battery. The electrostatic energy stored by it is

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

The energy required to charge a capacitor of $5\,\mu F$ by connecting a $d.c.$ source of $20\,kV$ is......$kJ$.