problem 436 at the interface between one linear dielectric and another
Question
Problem 4.36 At the interface between one linear dielectric and another, the electric field lines bend (see Fig. 4.34). Show that \tan \theta_{2} / \tan \theta_{1}=\epsilon_{2} / \epsilon_{1} assuming there
is no free charge at the boundary. [Comment: Eq. 4.68 is reminiscent of Snell's law in optics. Would a convex "lens" of dielectric material tend to "focus,"or "defocus," the electric field?]