$A$ capacitor of capacitance $10 \mu F$ is charged to $10 \text{ V}$. The energy stored in it is (in $\mu J$)

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: $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\, N\cdot m^2/C^2$]

Capacity of a capacitor is $48 \mu F$. When it is charged from $0.1 C$ to $0.5 C$,the change in the energy stored is:

$A$ battery is used to charge a parallel plate capacitor until the potential difference between the plates becomes equal to the e.m.f. of the battery. The ratio of the energy stored in the capacitor to the work done by the battery will be

Three identical capacitors are combined in different ways. For the same voltage applied to each combination,the one that stores the greatest energy is:

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).