lamp, electric

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Device designed to convert electrical energy into light energy.

In a filament lamp such as a light bulb an electric current causes heating of a long thin coil of fine high-resistance wire enclosed at low pressure inside a glass bulb. In order to give out a good light the wire must glow white-hot and therefore must be made of a metal, such as tungsten, that has a high melting point. The efficiency of filament lamps is low because most of the electrical energy is converted to heat.

A fluorescent lamp uses an electrical discharge or spark inside a gas-filled tube to produce light. The inner surface of the tube is coated with a fluorescent material that converts the ultraviolet light generated by the discharge into visible light. Although a high voltage is needed to start the discharge, these lamps are far more efficient than filament lamps at producing light.

Blue stands for the Pacific Ocean and water on which life depends. Yellow symbolizes the sun. Green represents the lush vegetation. Effective date: 18 November 1977. >>