1. (a) Derive the electric field wave equation for an electromagnetic wave that propagates through the plasma. (b) If a GEM with a frequency of 40 MHz is fired at ionosphere (plasma frequency = 20 MHz, collision frequency between particles is much smaller than plasma frequency), explain how the GEM propagates in the ionosphere. 2. (a) Derive the formulation of Snell's law, for the TM case. (b) Derive the Fresnell persamaan equation (reflection coefficient and transmission coefficient), for the case of TE 3. An electromagnetic wave comes from medium 1 to medium 2. Medium 1 has permetivitas & 1 and the permeability u 1. while medium 2 has permetivitas & 2 and permeability u 2. If & 1 = x & 2 and u 1 = y 2, Determine (express the result in x and y): (a) critical angle value. (b) the value of the Brewster angle. (c) with what angle of incidence the wave will wwwwwwwwww. fully transmitted. (d) Determine the reflection coefficient and transmission coefficient if the angle of incidence is equal to the critical angle. (e) Determine the reflection coefficient and transmission coefficient if the angle of incidence is equal to the angle of Brewster. (Review for TE case)