A parallel plate capacitor carries a charge $q$. The distance between the plates is doubled by application of a force. The work done by the force is
Zero
$\frac{{{q^2}}}{C}$
$\frac{{{q^2}}}{{2C}}$
$\frac{{{q^2}}}{{4C}}$
The work done in placing a charge of $8 \times {10^{ - 18}}$ coulomb on a condenser of capacity $100\, micro-farad$ is
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?
Energy per unit volume for a capacitor having area $A$ and separation $d$ kept at potential difference $V$ is given by
A parallel plate capacitor is charged fully by using a battery. Then, without disconnecting the battery, the plates are moved further apart. Then,
A parallel plate capacitor has an electric field of ${10^5}\,V/m$ between the plates. If the charge on the capacitor plate is $1\,\mu \,C$, the force on each capacitor plate is......$N$