Practice question

**Aerials produce radio waves** by rapid acceleration/deceleration of electrons in antenna driven by AC, frequency equals driving frequency, for 60 MHz, λ=c/f=3×10⁸/60×10⁶=5 m, half-wave antenna length λ/2=2.5 m, efficient radiation when antenna size comparable to λ. The document notes that Maxwell's equations predicted that light is an electromagnetic wave, confirmed by the fact that the speed of EM waves matched the speed of light. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Light is an electromagnetic wave, illustrating EM wave transverse nature and Maxwell's displacement current concept.