Practice question

**Greenhouse effect** IR absorbed by CO₂, H₂O, CH₄, warming Earth, excessive greenhouse due to fossil fuel burning raises temperature, EM waves role: Sun visible reaches surface, Earth emits IR trapped, altering energy balance, safety concern for climate change. The document mentions that UV lamps are used to kill germs in water purifiers due to their harmful effects on living organisms. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields To kill germs, illustrating EM wave transverse nature and Maxwell's displacement current concept.