Practice question

**Hertz experiment** used induction coil connected to two rods with gap, spark produced oscillating charge, emitted EM wave, received by loop with gap sparking when E induced, measured wavelength by standing wave, demonstrated EM wave properties, validating Maxwell. Using v λ = c , we have λ = (c/v) = (3 × 10⁸/40 × 10⁶) = 7.5 m . Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields 7.5 m, illustrating EM wave transverse nature and Maxwell's displacement current concept.