Question

Two equal and opposite charges Q1 = 2 C and Q2 = -2C are placed at a distance of 6m from each other. What is the potential at the midpoint between the two charges?

(a) 2 V

(b) 0 V

(c) 1 V

(d) 3 V

I have been asked this question by my college director while I was bunking the class.

Query is from Electrostatic Potential due to a System of Charges in portion Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

Correct choice is (b) 0 V

Explanation: Electric potential is a scalar quantity. So, the total potential will be the sum of all the individual charges.

V1 = \(\frac {kQ}{r} = \frac {2k}{3}\)

V2 = \(\frac {kQ}{r} = \frac {-2k}{3}\)

Total potential (V) = V1 + V2

V = k [ \((\frac {2}{3}) + (\frac {-2}{3})\) ]

V = 0 V

Therefore, the potential at the midpoint between the two charges is zero volt.