A cylindrical capacitor has charge $Q$ and length $L$. If both the charge and length of the capacitors are doubled, by keeping other parameters fixed, the energy stored in the capacitor

An electron enters a parallel plate capacitor with horizontal speed $\mu$ and is found to deflect by angle $\theta$ on leaving the capacitor as shown. It is found that $\tan \theta =0.4$ and gravity is negligible.

If the initial horizontal speed is doubled, then $\tan \theta$ will be:

A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is $3\times 10^4\text{ V/m}$, the charge density of the positive plate will be close to :

Two identical parallel plate capacitors of capacitance each are connected in series with a battery of emf, $E$ as shown. If one of the capacitors is now filled with a dielectric of dielectric constant $k$, the amount of charge which will flow through the battery is (neglect internal resistance of the battery)

In the figure is shown a system of four capacitors connected across a $10 \mathrm{V}$ battery. The charge that will flow from switch S when it is closed is:

What are the charges stored in the $1 \mu F$ and $2 \mu F$ capacitors in the circuit below, once the currents become steady?

A capacitor of $\mathrm{2 }\mathrm{\mu F}$ is charged as shown in the diagram. When the switch $\mathit{\text{S}}$ is turned to position $2$, the percentage of its stored energy dissipated is