# Electric Flux Density / Electric Field Intensity

by zaydana
Tags: density, electric, field, flux, intensity
 Sci Advisor PF Gold P: 1,765 The vector quantity B is not the electric flux density, it is the magnetic flux density (or magnetic field depending upon your reference). D is the electric flux density and is related to the electric field by $$\mathbf{D} = \epsilon \mathbf{E}$$ The boundary conditions for D and E are different. For example, the tangential E field is continuous across a boundary but the normal E field is discontinuous. The normal D across the boundary differs by the charge density that accumulates on the boundary so if we assume no bound charges then the normal D field is continuous, but the normal E field is still discontinuous if there is a change int he permittivity. So both the D and E fields can change between media depending upon the properties of the media but most cases will assume that no charges will build up on the interface and thus the D field can be continuous in more cases.