Practice question

**Radio waves** λ≈10⁻¹ to 10⁴ m, f≈10⁴ to 10⁹ Hz, produced by rapid acceleration/deceleration of electrons in aerials/antenna, used for long-distance communication because low frequency diffracts around obstacles and reflects from ionosphere, enabling ground wave and sky wave propagation, effective for broadcasting. Radio waves are typically produced by oscillating currents in macroscopic circuits (like antennas), while visible light arises from electron transitions between energy levels within atoms. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Different scales of oscillation, illustrating EM wave transverse nature and Maxwell's displacement current concept.