Fluorescent lamps produce light by combining electroluminescence and which of the following?

Fluorescent lamps produce light through a process that combines electroluminescence with phosphorescence. In a fluorescent lamp, an electric current passes through a gas, usually mercury vapor, which emits ultraviolet (UV) light. This UV light then excites a phosphor coating on the inside of the lamp, causing it to emit visible light.

Phosphorescence refers to the phenomenon where certain materials absorb energy and then re-emit it over a prolonged period. In the case of fluorescent lamps, the phosphor does not retain the energy for long, but it plays a crucial role in converting the UV light produced during electroluminescence into the visible spectrum we see. This combination is essential for the overall functioning of fluorescent lamps, as it allows them to produce more light efficiently than traditional incandescent bulbs, which rely solely on incandescence.

The other processes listed, such as incandescence, convection, and refraction, do not play a role in how fluorescent lamps generate light. Incandescence involves producing light by heating a material until it glows, convection relates to the transfer of heat, and refraction deals with the bending of light as it passes through different mediums.