$A$ charge of $20 \, C$ moves through a distance of $2 \, cm$. The work done is $2 \, J$. The potential difference between the two points is ........ $V$.

$A$ spherical shell of radius $R$ carries a charge $Q$. What is the potential at point $B$ on the surface,at the center $A$,and at point $C$ at a distance $R/2$ from the center?

Three concentric metallic shells $A, B$ and $C$ of radii $a, b$ and $c$ $(a < b < c)$ have surface charge densities $+\sigma, -\sigma$ and $+\sigma$ respectively. The potential of shell $B$ is

$A$ charge $Q$ is uniformly distributed over a long rod $AB$ of length $L$ as shown in the figure. The electric potential at the point $O$ lying at a distance $L$ from the end $A$ is

Two concentric hollow spheres of radii $r$ and $R$ $(R > r)$ have the same surface charge density $\sigma$. The total charge $Q$ is distributed between them. The electric potential at the common center is:

$A$ particle $A$ has charge $+q$ and particle $B$ has charge $+4q$,with each of them having the same mass $m$. When allowed to fall from rest through the same electric potential difference $V$,the ratio of their speeds $\frac{v_A}{v_B}$ will be: