Question

What is the dimension of volume charge density?

(a) [MLAT^-2]

(b) [M^0 L^-3 A T]

(c) [M L^-3 A T]

(d) [M L^-2 A T]

I had been asked this question in an online quiz.

This is a very interesting question from Basic Properties of Electric Charge in section Charges and Fields of Physics – Class 12

Answer 1

Correct option is (b) [M^0 L^-3 A T]

The best I can explain: Volume charge density = \(\frac {charge}{volume}=\frac {current*time}{volume}=\frac {A*T}{L^3}\)=[M^0 A T L^-3]. But in case of surface charge density, the dimension will be [M^0 L^-2 A T] because surface charge density means an electric charge in a unit area of the surface.