Question

Calculate electric potential due to a point charge of 10C at a distance of 8cm away from the charge.

(a) 1.125*10^13V

(b) 1.125*10^12V

(c) 2.25*10^13V

(d) 0.62*10^13V

This question was posed to me in an internship interview.

The above asked question is from Electrostatic Potential due to a Point Charge in section Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

The correct answer is (b) 1.125*10^12V

The explanation: In the SI system, electric potential due to a point charge at a distance r is \(\frac {q}{4\pi \varepsilon r}\)=9*10^9*\(\frac {q}{r}\). Substituting the values, we get potential=9*10^9*\(\frac {10}{0.08}\)V=1.125*10^12V. Though in practice, this huge value of electric potential is not present.