The work done to take an electron from rest where potential is $-60\, V$ to another point where potential is $-20\, V$ is given by.....$eV$.

Draw a graph showing the variation of electric potential $V$ with distance $r$ from the center for a uniformly charged spherical shell of radius $R$.

$A$ 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.

$A$ charge $Q$ is distributed over two concentric conducting thin spherical shells of radii $r$ and $R$ $(R > r)$. If the surface charge densities on the two shells are equal,the electric potential at the common centre is

Four electric charges $+q, +q, -q$ and $-q$ are placed at the corners of a square of side $2L$ (see figure). The electric potential at point $A$,midway between the two charges $+q$ and $+q$,is

$A$ pellet carrying a charge of $0.5\, C$ is accelerated through a potential difference of $2,000\, V$. What is the kinetic energy attained by the pellet?