An $\alpha$ particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two particals will be.

State which of the following is correct

As per this diagram a point charge $ + q$ is placed at the origin $O$. Work done in taking another point charge $ – Q$ from the point $A$ [co-ordinates $(0,\,a)$] to another point $B$ [co-ordinates $(a, 0)$] along the straight path $AB$ is

A square of side ‘$a$’ has charge $Q$ at its centre and charge ‘$q$’ at one of the corners. The work required to be done in moving the charge ‘$q$’ from the corner to the diagonally opposite corner is

Two positive charges of magnitude $q$ are placed at the ends of a side $1$ of a square of side $2a$. Two negative charges of the same magnitude are kept at the other corners. Starting from rest, if a charge $Q$, moves from the middle of side $1$ to the centre of square, its kinetic energy at the centre of square is