Electron volt is a unit of

Electron volt is a unit of

Electric potential at a point distant $0.5 \,m$ from a spherical conductor of radius $0.2 \,m$ charged to $+1 \,nC$ is

Charge $1.6 \times 10^{-7} \text{ C}$ is distributed uniformly over the surface of a spherical conductor of radius $R$. The ratio of the electric potential inside the spherical conductor to the electric field on the surface is . . . . . . .

$A$ 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.....$V$

Define $1 \ eV$.