Which of the following is a dimension of volt?

An electric point charge $10^{-3} \mu C$ is placed at the origin $(0, 0)$ of an $X-Y$ coordinate system. Two points $A$ and $B$ are situated at $(\sqrt{2}, \sqrt{2})$ and $(2, 0)$ respectively. The potential difference between the points $A$ and $B$ will be.....$volt$.

$1 \ eV = ...... \ J$. (Fill in the gap)

Two charges $8 \ \mu C$ each are placed at the corners $A$ and $B$ of an equilateral triangle of side $0.2 \ m$ in air. The electric potential at the third corner $C$ is

In a certain charge distribution,all points having zero potential can be joined by a circle $S$. Points inside $S$ have positive potential and points outside $S$ have negative potential. $A$ positive charge,which is free to move,is placed inside $S$. What will happen to the charge?

Derive an expression for the electric potential at a point due to a system of $N$ charges.