The energy which an $e^-$ acquires when accelerated through a potential difference of $1 \, V$ is called:

$A$ charge of total amount $Q$ is distributed over two concentric hollow spheres of radii $r$ and $R$ $(R > r)$ such that the surface charge densities on the two spheres are equal. The electric potential at the common centre is

Which of the following statements is correct?

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

Two concentric hollow metallic spheres of radii $r_1$ and $r_2$ $(r_1 > r_2)$ contain charges $q_1$ and $q_2$ respectively. The potential at a distance $x$ between $r_1$ and $r_2$ will be

The figure shows a charge array known as an electric quadrupole. For a point on the axis of the quadrupole,obtain the dependence of potential on $r$ for $r / a >> 1,$ and contrast your results with that due to an electric dipole,and an electric monopole (i.e.,a single charge).