White Modern Outdoor Indoor Low-pressure Mercury-vapor Compact Fluorescent Lamps

A fluorescent lamp, often known as a fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that produces visible light by fluorescence. An electric current in the gas stimulates mercury vapor, which creates short-wave ultraviolet light, which causes the lamp's phosphor coating to glow. In comparison to an incandescent lamp, a fluorescent lamp turns electrical energy into useable light far more efficiently. Fluorescent lighting systems have a luminous efficacy of 50a 100 lumens per watt, which is several times that of incandescent bulbs with equivalent light intensity. In comparison, an incandescent bulb's luminous effectiveness might be as low as 16 lumens per watt. Fluorescent light fittings are more expensive than incandescent lamp fixtures because they require a ballast to regulate the current through the lamp, among other factors.