Question

units of potential difference in cgs and mks system.

Answer 1

Potential difference is a measure of the work required to move a quantity of charge in an electrostatic field. Specifically, it is a measure of the potential energy per unit electric charge that is characterised by any point in an electric field. The dimension of potential difference are:
$Potentialdifference=\left[\frac{Work}{Charge}\right]=\left[\frac{\left(Mass\right){\left(Length\right)}^2}{\left(Current\right){\left(Time\right)}^3}\right]$

In the MKS system, potential difference is measure in $\frac{joule}{coulomb},orvolts$.

In the CGS system, potential difference is measure in millivolts or microvolts.