Incandescent Light Bulb

Incandescent light bulb are brilliant! The phenomenon of incandescence is that when a substance receives heat its temperature starts rising. As this continues, a stage approaches when the substance starts emitting light. This is because as its temperature rises its energy rises. There is a limit for this rise of energy. When this limit approaches, then the substance cannot any more store energy and therefore it starts emitting it as light.

The incandescent light bulb is a light, which contains a filament generally of tungsten that connects two electrodes. When electricity passes through the electrodes then these filament get heated. In addition, as result of this it emits out light. These lamps are the most economical at this point of time. Therefore, they are the lights that are in the widest use in the world at this movement.

The important parts of the incandescent lamps

it contains a glass bulb, low pressure inert gas, a tungsten filament, a contact wire going out of the stem, and similarly a stem wire that goes into the stem, support wires, stem having a glass mount, contact wire going out of stem, cap i.e. sleeve, insulation and an electrical contact.

Working of the lamp

There are two electrodes for the connection to the two electrodes. When, we connect these electrodes in the circuit, an electrical current passes through them. As the contact between them is through a filament having a high resistance, this filament opposes this passage of current. Because of this, it starts to heat up. When this heating reaches a limit, the filament starts emitting light.

The arrangement of the filament and the electrodes is in a compact glass bulb. In this bulb, there is very low atmospheric pressure. This low pressure of the atmosphere is also important for the filament to emit light.

When the filament becomes hotter, the some of the atoms of this filament come out of it in the vapor state. Because of this, the filament becomes thinner and thinner with the use. Eventually it breaks. This is how the life of these bulbs ends.

The atoms that come out of the filament deposit on the walls of the lamp. This may sometimes block the passage of the light.

Efficiency

They convert up to 90 % of the electrical energy in to heat and only the remaining into light.

Applications of the halogen lamps

These lamps can work at a very wide range of voltages. Therefore, they have very wide applications. They are used in devices that work on a voltages as low as 3 volts as in torches etc. alternatively they also work on high voltages as more than 100 volts as for the bulbs used in the lighting of big rooms etc.

Their stabilization time is very low like 0.10 seconds and they reach the 90% of their brightness in about 0.15 seconds.

They consume more power than the others do, for example the fluorescent lights. However as they are very cheap they are preferred over the other options.