Practice question

**Microwaves** λ≈10⁻³ to 0.3 m, f≈10⁹ to 10¹² Hz, produced by klystron/magnetron, used in microwave ovens because frequency ≈2.45 GHz matches rotational resonance of water molecules, causing dielectric heating, also radar, satellite communication due to small wavelength allows directional beams. Radio waves have long wavelengths, allowing them to diffract around obstacles and reflect off the ionosphere, facilitating wide-area coverage for broadcasting. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Long wavelength, illustrating EM wave transverse nature and Maxwell's displacement current concept.