Four point charges are fixed at the corners of a square of side kept in vacuum
PHYSICS · Subjective · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance
Problem
Four point charges are fixed at the corners of a square of side 10cm kept in vacuum. The charges are q1=+4.0μC, q2=−2.0μC, q3=+3.0μC and q4=+5.0μC, taken in order around the square.
(a) List all the charge pairs that contribute to the electrical potential energy of the system.
(b) Calculate the energy associated with each pair and hence find the total electrical potential energy of the configuration.
(c) State whether the assembly of these charges from infinity requires net work to be done by an external agent or results in net work being obtained. Justify your answer by referring to the sign of the total energy.