Practice question

**Microwaves in ovens** cause water molecules to rotate at 2.45 GHz, friction heats food, penetration depth few cm, efficient heating, also radar uses reflection of microwaves from objects, Doppler shift measures speed, medical diathermy uses microwaves for tissue heating. Microwaves can penetrate the atmosphere with minimal absorption and are easily directed into narrow beams, making them ideal for satellite communication over long distances. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Penetration and directionality, illustrating EM wave transverse nature and Maxwell's displacement current concept.