Which frequency range corresponds to the ultrahigh frequency (UHF) band used by cellular phones?
**Hertz experiment** produced radio waves using spark gap LC oscillator, detected with loop antenna, confirming Maxwell's prediction, frequency ≈10⁸ Hz, wavelength ≈3 m, demonstrating EM waves travel at c, transverse, can be reflected, refracted, polarized. The document mentions that cellular phones use radio waves in the UHF band, which typically falls within the general radio wave range of 500 kHz to 1000 MHz , but UHF specifically is higher, often around 300 MHz to 3 GHz . Here, we approximate within radio range. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f
Ref: NCERT > Physics Book > Electromagnetic Waves > Electromagnetic Spectrum - Radio Waves and Microwaves