Incandescent light Bulb

The incandescent lamp, incandescent light globe or incandescent bulb which produces light by heating a thing metal wire to a very high temperature and then it glows. The heated metal wire is protected from air by the glass bulb which is filed with the inert gas.  In the halogen bulb the chemical process which returns the metal into filament which prevents its evaporation. The lamp is supplied with electricity by wires embedded or feed-through terminals in the glass bulb.

Most devices we call light bulbs use electrical energy to excite atoms to produce photons. Photons are light energy. A typical incandescent light bulb is con­structed of a bulbous, thin-walled, glass envelope. Sealed inside the glass is an inert gas such as argon or nitrogen. Also inside the glass is an electrical cir­cuit. It consists of a resistor called a filament. The fil­ament allows current flow through it by means of a pair of contact terminals on the socket of the bulb. The filament is typically made out of tungsten. Current flow heats the tungsten filament up to a white-hot temperature. Like any heated metal, the tungsten be­comes white hot, something in the region of 4,500°F (2,500°C). A metal heated to these kinds of tempera­tures emits both heat and visible light in a reaction known as incandescence. Visible light energy is radi­ated as photons a typical vehicle incandescent light bulb. Incandescent light bulbs use a thermal radiation principle. Thermal radiation light bulbs are not espe­cially efficient because much of the electrical energy consumed is radiated as heat as well as photons. A typical light bulb lasts until the tungsten in the filament vaporizes, creating a high-resistance spot, following which the bulb burns out.

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