$A$ $5.0 \mu F$ capacitor is charged to a potential difference of $800 V$ and discharged through a conductor. The energy (in $J$) given to the conductor during the discharge is:

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

$A$ parallel plate air capacitor has capacity $C$,distance of separation between plates is $d$,and potential difference $V$ is applied between the plates. The force of attraction between the plates of the parallel plate air capacitor is

The plates of a parallel plate capacitor have an area of $90 \,cm^{2}$ each and are separated by $2.5 \,mm$. The capacitor is charged by connecting it to a $400 \,V$ supply.
$(a)$ How much electrostatic energy is stored by the capacitor?
$(b)$ View this energy as stored in the electrostatic field between the plates,and obtain the energy per unit volume $u$. Hence arrive at a relation between $u$ and the magnitude of electric field $E$ between the plates.

In steady state,the energy stored in the capacitor as shown in the figure is ..... $nJ$.

$A$ variable condenser is permanently connected to a $100 \ V$ battery. If the capacity is changed from $2 \ \mu F$ to $10 \ \mu F$,then the change in energy is equal to: