Q.7) a) Using Maxwell equation in phasor form, derive expression for the wave equation in free space. Please note that the vector Laplacian of E, is defined as VE, = V(V.E.)- V x V x E,. b) Consider a 10 Mhz plane wave propagating in water. At this frequency, losses in water are negligible (e" = 0). Assume in water, , 1 and e, = 55. Find 3, d, phase velocity, intrinsic impedance (7), E,, and Hy. Note that the electric field intensity have a maximum amplitude of 0.4 V/m.[CLO 3, PLO 3] %3D