Electromagnetic interactions derived from potentials: charge and magnetic dipole

Abstract

We discuss some elementary examples of interactions (at low velocity) between point charges and magnetic dipoles using potentials, along the lines indicated by Konopinsky, and show that the physical interpretation might look quite different than using fields. In particular Lorentz's force does not appear explicitly, and has different interpretations in different cases. Also, the scalar potential from a moving magnetic dipole appears as the potential from an equivalent electric dipole, and the electromagnetic momentum of the dipole in an electric field is a consequence of the mass-energy relationship.