In a non-polar - molecule, the centre of the nuclei and electron orbit overlap when such a molecule is positioned in electric field, the electrons are attracted with the positive charged of the anode and repelled by the negative charges of the cathode. Because of great attractive force exerted by the nucleus is placed , the electrons do not move away from their atoms but will undergo slight displacement within the atom itself in the direction of the positively charge electrode. The centres of nucleus and the electron orbit are displaced by a distance d. This displacement of electrons within the atom due to the effect of electric field is called "electronic polarization". As a result of electronic polarization the positive and negative charge in the atom of a dielectric are separated and behaves like an electric dipole.