If charge $+q$ is taken from one point to another over an equipotential surface, then

A charge $Q$ is placed at each corner of a cube of side $r$. The potential at the centre of the cube is ($\epsilon_0$ = permittivity of free space)

Select the 'WRONG' statement about polar molecules.

Two point charges placed in air separated by distance $R$ exert a force $F$ on each other. Now the space between those charges is filled with dielectric constant $K$. At distance $R_1$ between the charges, the same force is exerted as $F$. Then