4. In a dielectric medium(e = 9€0, μ = μo), a plane wave with H = 0.4 cos(10⁹t — qx - q√8z) ay A/m is incident on an air boundary at z = 0. Find (a) Or and Ot (b) q (c) The wavelength in the dielectric and in air (d) The incident E (e) The transmitted and reflected E (f) The Brewster angle