In the electric field of a point charge $q$, a certain charge is carried from point $A$ to $B$, $C$, $D$ and $E$. Then the work done

At a distance $l$ from a uniformly charged long wire, a charged particle is thrown radially outward with a velocity $u$ in the direction perpendicular to the wire. When the particle reaches a distance $2 l$ from the wire, its speed is found to be $\sqrt{2} u$. The magnitude of the velocity, when it is a distance $4 l$ away from the wire is (ignore gravity)

When a negative charge is taken at a height from earth's surface, then its potential energy

A particle has a mass $400$ times than that of the electron and charge is double than that of a electron. It is accelerated by $5\,V$ of potential difference. Initially the particle was at rest, then its final kinetic energy will be......$eV$

Four equal charges $Q$ are placed at the four corners of a square of each side is $'a'$. Work done in removing a charge $-Q$ from its centre to infinity is

Work done in moving a positive charge on an equipotential surface is