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. The document mentions that microwaves have wavelengths from 0.1 m to 1 mm . Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields 0.1 m to 1 mm, illustrating EM wave transverse nature and Maxwell's displacement current concept.