The in’s and out’s of Light Bulbs

Light bulbs are an indispensable electrical appliance that forms a very important part of all our daily activities. Yet we pay no heed to these small but highly useful appliances.
It takes a power failure to make us realize and appreciate the worth of the light bulb. Light bulbs can be formally referred to as incandescent lamps, incandescent globes and most often, as incandescent light bulbs.

Incandescent light bulbs work on the principle of incandescence which refers to the emission of light through the transfer of heat energy via the method of radiation. Incandescent light bulbs have a very thin filament.

This filament is made up of tungsten. The tungsten filament is protected inside an outer body made of glass. This filament is heated up by passing an electric current through it. Being excessively thin, the tungsten filament offers a considerable level of resistance to the electric current passing through it.

This resistance helps in converting the electrical energy into heat energy. The heat energy is considerably influential and turns the filament white hot. It is this extreme heat which is visible as white light. As a result of this copious heat energy the filament starts to glow. This glow is the incandescence emitted by the light bulbs and this characteristic is responsible for the name “incandescent light bulbs”.

The glass casing stops the oxygen in the air from coming into contact with the filament as it would lead to oxidation of the filament. Incandescent light bulbs are available in a variety of sizes. Also the voltage of bulbs can differ greatly, ranging from as low as 1.5 volts to as powerful as 300 volts.

Some of the advantages of incandescent light bulbs are that they do not need any external equipment for regulating, and also the cost of producing these bulbs is very low. incandescent light bulbs are extremely convenient as they work well regardless of the current being used, be it Direct Current that is D.C or Alternating Current that is A.C.

Due to the extremely adaptable nature of these bulbs, they are widely used in homes as well as in offices for commercial purposes. Let us now observe the construction and structure of the incandescent light bulbs. The incandescent light bulbs are made of a glass casing which is called the envelope. This glass casing is filled with an inert gas. This inert gas works towards decreasing the evaporation of the filament.

This filament is made out of a wire of tungsten. An electric current is passed through this tungsten wire. The electric current causes the filament to heat up. The filament upon heating releases a light which forms a sort of continuous light spectrum.

Visible light is the functional and useful part of the light spectrum. However a major of the light emitted falls in the spectrum of infrared wavelengths. The glass casing of an incandescent light bulb can obtain temperatures approximating 400 to 550 degrees Fahrenheit which is the same as 200 to 260 degrees Celsius.