if a di-electric was introduced to an electric field from the outside it would be polarized and the charge denisties would be as follows : **volume bounded charge density ( ρv ) = - div ( P ) **surface bounded charge density ( ρs ) = P . n where P is the polarization vector and n is the unit vector. now if the di-electric was originally neutral , should all these bounded charges sum up to zero ? ( volume bounded charge density ρv + surface bounded charge density ρs = 0 ) ? and what if the source of the electric field was coming from inside the di-electric ( as for example a free point charge ) would it still be the case ?