Distinguish between electric potential and electric potential energy.

$A$ hollow conducting sphere of radius $R$ has a charge $(+Q)$ on its surface. What is the electric potential within the sphere at a distance $r = \frac{R}{3}$ from its centre?

If $50 \, J$ of work must be done to move an electric charge of $2 \, C$ from a point,where potential is $-10 \, V$ to another point,where potential is $V \, V$,the value of $V$ is ......... $V$.

The figure shows a charge array known as an electric quadrupole. For a point on the axis of the quadrupole,obtain the dependence of potential on $r$ for $r / a >> 1,$ and contrast your results with that due to an electric dipole,and an electric monopole (i.e.,a single charge).

Two particles with charges $+q$ and $-q$ are separated by a distance of $2d$. What is the electric potential at the midpoint of the line joining them?

Concentric metallic hollow spheres of radii $R$ and $4R$ hold charges $Q_1$ and $Q_2$ respectively. Given that surface charge densities of the concentric spheres are equal,the potential difference $V(R) - V(4R)$ is