Question

What is the dimension of electric potential?

(a) [M L T^-2]

(b) [M L T^-3 I]

(c) [M L T^-3 I^-1]

(d) [M L^2 T^-3 I]

This question was posed to me in an online interview.

Question is taken from Electrostatic Potential topic in portion Electrostatic Potential and Capacitance of Physics – Class 12

Answer 1

Right answer is (c) [M L T^-3 I^-1]

To explain: Potential can be simply defined as work done on a unit charge, therefore the dimension=\(\frac {the \, dimension \, of \, work}{the \, dimension \, of \, charge}=\frac {[M L T^{-2}]}{[I T]}\)=[M L T^-3 I^-1]. The dimension of potential energy in mechanics is not the same as electric potential energy though both of them are the unit of energy. In mechanics, it is defined as work done on a unit mass.