If initial charge on all the capacitors were zero, work done by the battery in the circuit shown is ........... $mJ$

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

A $600\; pF$ capacitor is charged by a $200\; V$ supply. It is then disconnected from the supply and is connected to another uncharged $600\; pF$ capacitor. How much electrostatic energy is lost in the process?

A parallel plate capacitor is made of two square parallel plates of area $A$ , and separated by a distance $d <  < \sqrt A $ . The capacitor is connected to a battery with potential $V$ and allowed to fully charge. The battery is then disconnected.  A square metal conducting slab also with area $A$ but thickness $\frac {d}{2}$ is then fully inserted between the plates, so that it is always parallel to the plates. How much work has been done on the metal slab by external agent while it is being inserted?

A capacitor of capacitance $C$ is charged to potential difference $V_0$. Now this capacitor is connected to an ideal inductor. When $25\%$ of energy of capacitor is transferred to inductor then at that time what will be potential difference across capacitor