What is "incandescent light bulb"

Incandescent \In`can*des"cent\, a. [L. incandecens, -entis, p. pr. of incandescere to become warm or hot; pref. in- in + candescere to become of a glittering whiteness, to become red hot, incho. fr. candere to be of a glittering whiteness: cf. F. incandescent. See Candle.] White, glowing, or luminous, with intense heat; as, incandescent carbon or platinum; hence, clear; shining; brilliant.

Holy Scripture become resplendent; or, as one might say, incandescent throughout.
--I. Taylor.

Incandescent lamp, Incandescent light, Incandescent light bulb (Elec.), a kind of lamp in which the light is produced by a thin filament of conducting material, now usually tungsten, but originally carbon, contained in a vacuum or an atmosphere of inert gas within a glass bulb, and heated to incandescence by an electric current. It was inventerd by Thomas Edison, and was once called the Edison lamp; -- called also incandescence lamp, and glowlamp. This is one of the two most common sources of electric light, the other being the fluorescent light, fluorescent lamp or fluorescent bulb.

An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to a high temperature, by passing an electric current through it, until it glows with visible light ( incandescence). The hot filament is protected from oxidation with a glass or quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is prevented by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electric current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent lamp is widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting.

Incandescent bulbs are much less efficient than most other types of electric lighting; incandescent bulbs convert less than 5% of the energy they use into visible light, with standard light bulbs averaging about 2.2%. The remaining energy is converted into heat. The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps. Some applications of the incandescent bulb deliberately use the heat generated by the filament. Such applications include incubators, brooding boxes for poultry, heat lights for reptile tanks, infrared heating for industrial heating and drying processes, lava lamps, and the Easy-Bake Oven toy. Incandescent bulbs typically have short lifetimes compared with other types of lighting; around 1,000 hours for home light bulbs versus typically 10,000 hours for compact fluorescents and 30,000 hours for lighting LEDs.

Incandescent bulbs have been replaced in many applications by other types of electric light, such as fluorescent lamps, compact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diode lamps (LED). Some jurisdictions, such as the European Union, China, Canada and United States, are in the process of phasing out the use of incandescent light bulbs while others, including Colombia, Mexico, Cuba, Argentina, Brazil and Australia, have prohibited them already.