Two condensers of capacity $0.3\,\mu F$ and $0.6\,\mu F$ respectively are connected in series. The combination is connected across a potential of $6\,volts$. The ratio of energies stored by the condensers will be

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)

The energy stored in the condenser is

If an electron enters into a space between the plates of a parallel plate capacitor at an angle $\alpha $ with the plates and leaves at an angle $\beta $ to the plates, the ratio of its kinetic energy while entering the capacitor to that while leaving will be

$A$ $2$ $\mu F$ capacitor is charged to a potential $=$ $10\,V$. Another $4$ $\mu F$ capacitor is charged to a potential $=$ $20\,V$. The two capacitors are then connected in a single loop, with the positive plate of one connected with negative plate of the other. What heat is evolved in the circuit?......$\mu J$

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.