$A$ capacitor of $6 \ \mu F$ is charged from $10 \ V$ to $20 \ V$. The increase in its stored energy is:

When an uncharged capacitor is connected to a battery to charge it fully,

An uncharged capacitor is connected to a battery. On charging the capacitor,

The energy stored in the electric field produced by a metal sphere is $4.5\, J$. If the sphere contains $4\,\mu C$ charge,its radius will be.......$mm$. [Take: $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\, N\cdot m^2/C^2$]

$A$ $4\ \mu F$ capacitor is charged to $400\ V$ and then connected to a $1\ k\Omega$ resistor. How much heat energy in $J$ is produced?

$A$ parallel plate capacitor having plate area $A$ and separation $d$ is charged to a potential difference $V$. The charging battery is disconnected and the plates are pulled apart to four times the initial separation. The work required to increase the distance between the plates is ($\epsilon_0 =$ permittivity of free space).