Question

n is specifeid to measure the learning outcome (e) he instantaneous expression for the magnetic field intensity is plane wave ina this question given by H (r)-4x10 cos(10'art_ßy + 4), A/m Determine a) T b) The wave phase constant β he instantaneous expression of electric field intensity ECt) 12pts 12pt

Answer 1

using poynting theorem, E times H = P where E, H & P are electric field magnetic field & propagation direction respectively electric field direction = ? Magnetic field direction = a_z propagation direction = a_y Therefore ? X a_z = a_y: vector identies a_x times a_y = a_z a_z times a_x = a_y a_y times a_z = a_x electric field direction implies -a_x also E_o/H_o = n = 377 (intrinsic impedance in air) H_o = 4 times 10^6 Therefore E_o = 377 times 4 times 10^6 V/m Therefore E_(t) = -1.508 times 10^9 cos (10^7 times pi t - beta y + pi/4) a_x V/m (6) omega/beta = 3 times 10^8 rightarrow in air medium 10^7 pi/3 times 10^= beta: beta = 10 pi/3 = 3.33 pi rad.