Why is the filament of incandescent lamp spiral?

The high-temperature resistant metal wires in filament, bulb or electron tube are mostly thin tungsten wires, and titanium or other alloys are also useful. After being electrified, it can directly emit light and heat, or emit electrons and ultraviolet rays, excite high-energy electric fields or fluorescent substances such as high-energy rays and rare gases, or form plasma. , and produce various colors of visible light. The earliest white-red filament was invented by Edison's experimental research. Pure resistance electrical appliances that convert electric energy into internal energy and then into light energy after being electrified, mainly into light energy. Why is the filament of white and red light spiral? There are four main reasons: 1. White-red light is the high-temperature luminescence produced by charged resistance wire. The spiral shape is beneficial to the concentration of heat energy and ensures that the electric lamp emits light according to the rated power. 2. Through the spiral, the filament length is increased, the filament diameter is reduced, and the filament resistance is improved. So that the light-emitting area of the electric lamp is large and the brightness is higher. 3. Make the filament more flexible and avoid vibration damage. 4, conductor resistance is related to the conductor section and length, if it is a straight line, small bulbs can not be installed in uninhabitable places! Therefore, the filament coil of the bulb forms a spiral shape.