Problem 1. Maxwell's equations (10 points)
(a) Show that from the Maxwell's equations in charge-free, homogeneous, isotropic medium, one can derive a waveform equation for both E and H fields, respectively. Hint: use the vector identity (A × B) × C = (A · C)B - (B · C)A.
(b) Show that the plane wave solutions E = E₀exp[i(k · r - ωt)] and H = H₀exp[i(k · r - ωt)] where E₀ and H₀ are space and time independent vectors, are indeed the solution for the wave equation derived from the Maxwell's equations, and the speed of the electromagnetic waves satisfy the following relation: υ = ω/k = 1/√(εμ).
(c) Show that k · E = 0, k · H = 0, H = k × E/ωμ, and E = H × k/ωε, showing that E, H, and k are orthogonal to each other, demonstrating the transverse nature of the waves.
(d) Find the time-averaged Poynting vector within a period of oscillation for this wave. What does this say about the direction of energy flow?