Given the electric field of a 200 MHz uniform plane wave propagating in the z^ direction, where E is parallel to the y axis and reaches a peak value of 150 (mV/m) at t = 0 (s) and z = 0.5 (m).
(a) Write the expression for the electric field of the wave in free space.
(b) Write the expression for the electric field of the wave in polystyrene (µr = 1, er = 2.53).