Dielectric boundary conditions. At the interface between two dielectric materials with dielectric constants ε1 and ε2, the electric field intensity everywhere in material 1, � 1, has magnitude 1 and makes an angle α1 with the normal to the interface between the materials. There is a charge with surface charge density rhos sandwiched between the two materials. Determine the charge density rhos such that the electrical field intensity in material 2, �2 , is exactly equal to � 1.