Question

Six equal point charges Q = 10nC are located at 2,3,4,5,6,7m. Find the potential at origin.

(a) 140.35

(b) 141.35

(c) 142.35

(d) 143.35

This question was posed to me in an online interview.

Origin of the question is Electric Potential topic in section Electrostatic Fields of Electromagnetic Theory

Answer 1

Right choice is (d) 143.35

Best explanation: V = (1/4πεo) ∑Q/r = (10 X 10^-9/4πεo)

(0.5 + 0.33 + 0.25 + 0.2 + 0.166 + 0.142) = 143.35 volts.