An electron of charge $e$ coulomb passes through a potential difference of $V$ volts. Its energy in joules will be

Two identical positive charges are placed at $x = -a$ and $x = a$. The correct variation of potential $V$ along the $x$-axis is given by:

$A$ charge of $10^{-9} \, C$ is placed on each of the $64$ identical drops of radius $2 \, cm$. They are then combined to form a bigger drop. Find its potential.

$A$ charge of $10\, e.s.u.$ is placed at a distance of $2\, cm$ from a charge of $40\, e.s.u.$ and $4\, cm$ from another charge of $20\, e.s.u.$ The potential energy of the charge $10\, e.s.u.$ is (in $ergs$)

Define electric potential and explain it. Write its $SI$ unit and give its other units.

$A$ charge $Q$ is distributed over two concentric hollow spheres of radii $r$ and $R$ $(R > r)$ such that their surface charge densities are equal. The potential at the common centre is