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

If the charge on the capacitor is increased by $3 \ C$,the energy stored in it increases by $44 \%$. The original charge on the capacitor is (in $C$)

In steady state,the energy stored in the capacitor as shown in the figure is ..... $nJ$.

$A$ $700\,pF$ capacitor is charged by a $50\,V$ battery. The electrostatic energy stored by it is

An air-filled parallel plate capacitor has a uniform electric field $E$ in the space between the plates. If the distance between the plates is $d$ and the area of each plate is $A$,the energy stored in the capacitor is ($\epsilon_{0} =$ permittivity of free space).

Write three different formulas for the energy stored in a capacitor.