Question

Three point charges 1C, 2C and 3C are placed at the corners of an equilateral triangle of side 1m. Calculate the work required to move these charges to the corners of a smaller equilateral triangle of side 0.5 m as shown in Figure (A)

Answer 1

As potential energy of two charges separated by a distance r is given by U = [q₁q₂/4πε₀r], the initial and final potential energy of the system will be

So work done in changing the configuration of the system