Two point charges A = +3 nC and B = +1 nC are placed 5 cm apart in air. The work done to move charge B towards A by 1 cm is

The potential energies associated with four orientations of an electric dipole in an electric field are

(i) $$-5U_0$$ (ii) $$-7U_0$$ (iii) $$3U_0$$ (iv) $$5U_0$$

where $$U_0$$ is positive. Rank the orientations according to the angle between the electric dipole moment p and electric field E, greatest first