Why does bulb glow

The typical incandescent light bulb contains a thin wire usually tungsten called a filament that has a high electrical resistance. This filament gets very hot when an electric current passes through it. The intense temperature makes the filament glow brightly. If oxygen were present the glowing hot filament would burn up. For combustion as we know it, oxygen must be present. Thus on Earth the glass globe around the filament is necessary to keep the filament isolated from the oxygen in the air.

It also protects us from the exposed wires and hot filament. Since there is no air oxygen in outer space, a filament without a glass covering would simply glow and not be consumed by traditional burning. Actually, the filament gets so hot it literally boils off atoms and electrons. Sometimes this material collects as a dark spot at the top of the bulb. Eventually the filament deteriorates, becomes weak, and breaks, thus ending the life of the light bulb.

In some bulbs the filament can even burn hotter and thus give off more light if a particular type of gas is present in the bulb. Whenever n electric current goes through the filament, the filament glows.

It may also be known as the electron emitting element in a vacuum tube. The incandescent light bulb turns electricity into light by sending the electric current through a thin wire called a filament.

Electrical filaments are made up mostly of tungsten metal. The resistance of the filament heats the bulb up. Eventually the filament gets so hot that it glows , producing light. Is Thomas Edison's first light bulb still burning? Livermore, California, is home to what residents say is the world's longest-burning light bulb. Thomas Edison, the inventor of the incandescent light bulb, would be proud. The bulb is 3 inches long and made of hand-blown glass and carbon filament.

What is the working principle of bulb? An incandescent bulb works on the principle of incandescence, a general term meaning light produced by heat. In an incandescent type of bulb, an electric current is passed through a thin metal filament, heating the filament until it glows and produces light.

What are the different types of light bulbs? Here is the list of five most common types of Light Bulbs along with their respective advantages. How do electrons light a bulb? Incandescent light bulbs have a small filament which when heated begins to glow and emit light.

Here energy is being taken from the electrons because of the interactions with the atoms in filament which causes those atoms to heat up, which in turn makes them emit light. What happens inside a light bulb? When you turn on a light bulb, electricity flows through the filament. As the filament heats up it produces light. If the bulb had air inside of it the filament would quickly heat up and essentially burn up. However, a light bulb contains a vacuum or a specialized gas that doesn't allow the filament to burn.

In addition, if the glass breaks it is possible to get cuts. These hazards can be reduced by ensuring the bulb is cool to the touch before grasping it and by holding it firmly but not squeezing by the fattest part of the glass while rotating counter-clockwise until it comes completely loose. Although we say the filament "burns out" it actually vaporizes over time. Some of it can be seen as darkening on the glass where it has solidified. The gas inside the glass envelope is argon, which is used because it is inert and therefore cannot unite with the filament.

The brightness of the filament can be varied by changing the amount of current flowing through it the amperage , or the voltage between ends, as the amperage is related to the voltage by Ohm's law. Also, as the filament ages, its brightness will diminish somewhat and its light will get redder and redder.

Eventually, all filaments will slowly vaporize and fail due to the high temperature caused by the electricity flowing through it. By design, a light bulb has no oxygen in it.

The manufacturer fills it with an inert gas like argon or nitrogen. However, this does not prevent atoms from popping off the surface of the filament due to the intense heat.

This makes the filament thinner and thinner. Eventually, it becomes so thin that it breaks. For a short period of time, the two broken ends are very close to each other, and electricity can jump across in a bright blue spark.

However, the two broken ends soon fall away from each other, breaking the spark, and the bulb will light no more. It has changed the world by letting people do work at night.

Previously this was very hard to do because other light sources such as candles or fires did not provide enough light. Travel: Night travel by automobiles has largely been made possible by the light bulb.

Also, lighthouses all over the world use very powerful light bulbs, and this provides the right guidance for all ships. Medicine: All internal and non-intrusive medical procedures use variants of the original light bulb. Mining: Earlier, underground miners used torches, which also added to the carbon dioxide content in the air, and therefore made breathing difficult. With the advent of light bulbs, mining has also become healthier and safer.

In coal mines, the risk of explosion of the coal dust contained in the air was so high that conventional fire lanterns couldn't be used they used a tepid metal mesh covered lanterns , with light bulbs coal mining became much safer. War: The development of the light bulb allowed searchlights to be built which could find enemy aircraft, eliminating the risk of being bombed by surprise. Apart from this, the light bulb is used in various other fields including communications, sports, etc.

Electric Power Generators were needed before light bulbs could be put into people's homes. Replacement for unsafe candles or gas lighting was the initial driver for creating a Power Distribution Network , to put electric wires into the homes of ordinary people. The filament that could 'burn' for many hours had to be developed before people would consider buying a light bulb. Initial development focused on electrifying business areas of cities with lighting for the streets and offices.

Electric wires of sufficient quality and manufacture had to be invented. The bulb needed to have most of the air evacuated from it to prolong the life of the filament — therefore a vacuum pump. A means to properly insulate the wires, connect the wires to one another and equipment had to be developed to safely distribute the power.

Techniques and equipment had to be invented to transmit power over long distances — hence Nikola Tesla's development of AC Alternating Current and high voltage transmission lines. Fuses and later circuit breakers had to be developed to avoid damaging the entire line or inaccessible portions thereof. The electric light bulb was also the genesis for many other inventions based on electricity, including the vacuum tube that led to the transistor used in almost all electronic devices in use today.

After people had electricity being delivered to their houses and places of work, inventions such as washing machines, electric irons, motors, radios could take advantage of the convenient source of power available needed to run them.

Without the electric light bulb, the world that we live in would be very different. The parent to the modern fluorescent lamp was invented in the late s by Peter Cooper Hewitt.