Which type of electromagnetic waves are produced by special vacuum tubes like klystrons and magnetrons?
**Radio waves** effective for long-distance communication because low frequency waves diffract around Earth curvature and reflect from ionosphere, enabling beyond line-of-sight, used in AM (≈10⁶ Hz) ground wave, short wave sky wave. Microwaves used for satellite due to high frequency penetrates ionosphere and directional beam. The document mentions that microwaves are produced by special vacuum tubes such as klystrons and magnetrons. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Microwaves, illustrating EM wave transverse nature and Maxwell's
Ref: NCERT > Physics Book > Electromagnetic Waves > Applications of EM Waves in Communication and Medicine