Four equal point charges are placed at the corners of a square of side
PHYSICS · Subjective · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
Four equal point charges +Q are placed at the corners of a square of side a. A small test charge qt is initially at the centre O of the square.
(a) Show that the electric potential at O due to the four charges is 4πϵ04(a/2)Q.
(b) The test charge is slowly moved from O to one of the mid-points M of a side of the square.
(i) Calculate the work done in this displacement.
(ii) If the same displacement O → M is carried out along two different paths—one straight and the other broken into two segments—verify numerically that the work done is the same for both paths.
(c) The charge qt is now taken once around the closed path O → M → corner C → O. Determine the net work done in this closed journey and justify your answer.