Question

A point charge 0.4nC is located at (2, 3, 3). Find the potential differences between (2, 3, 3)m and (-2, 3, 3)m due to the charge.

(a) 2.5

(b) 2.6

(c) 2.7

(d) 2.8

I had been asked this question by my school teacher while I was bunking the class.

This key question is from Electric Potential topic in chapter Electrostatic Fields of Electromagnetic Theory

Answer 1

Right option is (c) 2.7

Easiest explanation: Vab = (Q/4πεo)(1/rA) + (1/rB), where rA and rB are position vectors  rA = 1m and rB = 4m. Thus Vab = 2.7 volts.