All Problems

Electric Capacitance, Energy of an Electric Field

Problem 3.138

A spherical shell of radius \(R_{1}\) with a uniform charge \(q\) has a point charge \(q_{0}\) at its centre. Find the work performed by the electric forces during the shell expansion from radius \(R_{1}\) to radius \(R_{2}\)

Reveal Answer
A=q(q0+q/2)4πε0(1R11R2)A=\frac{q\left(q_{0}+q / 2\right)}{4 \pi \varepsilon_{0}}\left(\frac{1}{R_{1}}-\frac{1}{R_{2}}\right)