$A$ radius of a spherical charged shell is $10 \ cm$ and the electric potential on its surface is $100 \ V$. Then,the potential at $2 \ cm$ from the centre of the shell will be $.......$ (in $V$)

$A$ small conducting sphere of radius $r$ is lying concentrically inside a bigger hollow conducting sphere of radius $R$. The bigger and smaller spheres are charged with $Q$ and $q$ respectively $(Q > q)$ and are insulated from each other. The potential difference between the spheres will be

If an electron moves from rest from a point at which potential is $50\, V$ to another point at which potential is $70\, V$,then its kinetic energy in the final state will be:

$A$ 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 ........ $V$.

Calculate the electric potential on the axis of a disc of radius $R$ due to a charge $Q$ uniformly distributed on its surface.

If the electric potential at a distance of $5 \, cm$ from the center of a charged conducting sphere of radius $10 \, cm$ is $V$,then what will be the potential at a point at a distance of $15 \, cm$ from the center?