The work which is required to be done to make an arrangement of four particles each having a charge $+q$ such that the particles lie at the four corners of a square of side $a$ is …….

Explain electrostatic potential energy difference and give the noteworthy comments on it.

$n$ the rectangle, shown below, the two corners have charges ${q_1} = – 5\,\mu C$ and ${q_2} = + 2.0\,\mu C$. The work done in moving a charge $ + 3.0\,\mu C$ from $B$ to $A$ is………$J$ $(1/4\pi {\varepsilon _0} = {10^{10}}\,N{\rm{ – }}{m^2}/{C^2})$

An alpha particle is accelerated through a potential difference of ${10^6}\,volt$. Its kinetic energy will be……$MeV$

Two identical thin rings, each of radius $R $ meter are coaxially placed at distance $R$ meter apart. If $Q_1$ and $Q_2$ coulomb are respectively the charges uniformly spread on the two rings, the work done in moving a charge $q$ from the centre of one ring to that of the other is