Two capacitors of capacitance $2 \ \mu F$ and $4 \ \mu F$ are connected in series. If a potential difference of $10 \ V$ is applied across this combination,what will be the ratio of the energy stored in these capacitors?

If the distance between the plates of a capacitor with capacitance $C$ and charge $Q$ is doubled,the work done is:

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

The mean electric energy density between the plates of a charged capacitor is (here $q$ = charge on the capacitor and $A$ = area of the capacitor plate).

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).

$A$ battery does $200 \, J$ of work in charging a capacitor. The energy stored in the capacitor is ......... $J$.