If a charged spherical conductor of radius $10\,cm$ has potential $V$ at a point distant $5\,cm$ from its centre,then the potential at a point distant $15\,cm$ from the centre will be

$A$ charge $Q$ is distributed over three concentric spherical shells of radii $a, b, c$ $(a < b < c)$ such that their surface charge densities are equal to one another. The total potential at a point at distance $r$ from their common centre,where $r < a$,would be

An electron is accelerated through a potential difference of $2.5 \ V$. The energy gained by the electron is . . . . . . . (Charge of an electron = $1.6 \times 10^{-19} \ C$)

The electric potential at a distance of $R/2$ from the center of a charged conducting sphere of radius $R$ is .......

What is the electric potential at point $A$ due to the given charges?

$A$ metal sphere of radius $r$ carrying charge $q$ is placed at the center of a metallic shell of radius $R$ carrying charge $Q$. Find the expression for the potential difference between the sphere and the shell.