$A$ charge $2\,\mu C$ is taken from infinity to a point in an electric field,without changing its velocity. If the work done against the electric forces is $20\,\mu J$,then the potential at that point will be.....$V$

Two rings of radius $R$ are placed coaxially at a distance $R$ apart. They carry charges $Q_1$ and $Q_2$ respectively. How much work is required to move a charge $q$ from the center of one ring to the center of the other?

$A$ charge $+q$ is distributed over a thin ring of radius $r$ with line charge density $\lambda = q \sin^2 \theta / (\pi r)$. Note that the ring is in the $XY$-plane and $\theta$ is the angle made by the position vector with the $X$-axis. The work done by the electric force in displacing a point charge $+Q$ from the centre of the ring to infinity is

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

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 ......... $V$.

$A$ hollow metal sphere of radius $15 \,cm$ is charged such that the potential on its surface is $20 \,V$. Then, the potential at the centre of the sphere is (in $V$)