Question

Three positive charges are kept at the vertices of an equilateral triangle. We can make the potential energy of the system zero by adjusting the amount of charges. This statement is ______

(a) True

(b) False

I had been asked this question during an interview.

I'm obligated to ask this question of Electrostatic Potential due to a Point Charge in section Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

Right choice is (b) False

The explanation: Electric potential is a positive quantity if both the charges are positive. In this case, all the three charges are positive; hence there is no negative term in the total energy term. Therefore, we cannot make the total energy of the system zero by adjusting the values of charge. But it would be possible if one of the charges were positive.