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

The energy stored in a capacitor of capacitance $10 \mu F$ when charged to a potential of $6 \text{ kV}$ is: (in $\text{ J}$)

The energy stored in a capacitor of capacity $C$ which has been raised to a potential $V$ is given by

$A$ capacitor of capacitance $C$ is fully charged. It is discharged through a small coil of negligible resistance embedded in a thermally insulated block of mass $m$ and specific heat capacity $S$. If the temperature of the block rises by $\Delta T$,find the potential difference across the capacitor.

If the potential difference across a capacitor is increased from $5 \,V$ to $15 \,V$, then the ratio of final energy to initial energy stored in the capacitor is

The energy of a charged capacitor is given by the expression ($q$ = charge on the conductor and $C$ = its capacity).