Which statement best distinguishes incandescent lamps from fluorescent lamps?

• A. Fluorescent bulbs rely on gas discharge to produce ultraviolet light that excites phosphors to emit visible light
• B. Incandescent bulbs convert most energy to heat before producing light; fluorescent bulbs rely on gas discharge to produce ultraviolet light that excites phosphors to emit visible light
• C. Incandescent bulbs use chemical reactions to produce light
• D. Both types generate light in exactly the same way

Answer: (B)

Light is produced in incandescent bulbs by heating a filament until it emits visible light as thermal radiation. In fluorescent bulbs, electricity creates a discharge in a gas inside the tube, which emits ultraviolet light that then excites a phosphor coating to glow in the visible range. This two-step process makes fluorescent lamps more energy-efficient because less energy is lost as heat, unlike incandescent bulbs that convert much of the energy directly into heat.