The filament is the part of the light bulb that produces light. Filaments in incandescent light bulbs are made of tungsten. When electric current goes through the filament, the filament glows. It may also be known as the electron-emitting element in a vacuum tube. The filament must be heated to produce light, and it usually stays hot for several minutes after being turned off.
The filament needs to be connected to electricity to work, but it can also operate without power if there is enough oxygen present in the atmosphere to cause an arc between two wires. This happens naturally when a light bulb is not installed properly or burns out, but it can also be done intentionally by high-voltage enthusiasts who connect their light bulbs directly into an arc test lamp.
There are two types of filaments in light bulbs: carbon and tungsten. Carbon filaments are used in inexpensive light bulbs and have poor heat retention properties. They contain around 95% carbon by weight with the remaining 5% being other elements such as nitrogen and phosphorus. Tungsten filaments are stronger and more heat-resistant than carbon filaments and they make up about 95% of all filaments used in lighting applications. They contain around 92% tungsten by weight with the rest being other elements.
The incandescent light bulb converts energy into light by passing it via a tiny wire known as a filament. The majority of electrical filaments are constructed of tungsten metal. The filament's resistance warms the bulb. The filament eventually becomes so heated that it glows, emitting light. The brightness of an incandescent lamp is controlled by two factors: the power consumed and the length of time the bulb is activated.
Comparing lamps of equal power but different lengths of time active will reveal their relative brightness. A short period of time will make a more powerful lamp appear less bright because it consumes more electricity per unit of area than a low-power lamp. Longer periods will show them to be of equal intensity because they consume about the same amount of electricity.
Another way to compare bulbs of different types but same power is to measure their luminous flux. The luminous flux of a bulb is the amount of light it emits over a given period of time. It is expressed in lumens and represents the total light emitted by the bulb over one second of time. To convert this number to watts, you need to know its effective output area. The effective output area of a bulb is the area of one side of the glass bulb divided by the distance between its centers. For example, if the glass bulb has a diameter of 8 inches and there is 1 inch between its centers, then the effective output area is 0.125 square inches.
Light is emitted when the filament becomes hot enough to emit electrons that migrate to the colder end of the filament where they re-combine with these electrons, restoring the filament to its original temperature state.
There are other types of light bulbs on the market today. One of the most popular is the compact fluorescent lamp or CFL. These lamps use about 10% as much electricity as an incandescent lamp but they contain mercury which can leak out and cause damage to the environment if not disposed of properly. CFLs will continue to emit light even after being turned off so they should be placed in a cupboard or closet where they will not be disturbed for several months.
The laser beam from a DVD player or computer monitor is actually a stream of electrons that has been excited by an electric field. When this stream hits the phosphors on the disc itself, it stimulates them to glow like an oil lamp does. The human eye is very sensitive to blue light so lasers used in DVDs and video games tend to use this wavelength of light to achieve their effects.
Sodium lights have become increasingly popular in recent years due to their durability and efficiency.
An electric current is carried through a thin metal filament in an incandescent bulb, heating it till it glows and creates light. Because of tungsten's high melting point, incandescent lamps generally employ a tungsten filament. A carbon filament would have to be heated to about 3000°C (5500°F) before it would glow, which is well beyond the tolerance of most glass materials.
The color of the light depends on the composition of the filament. Tungsten contains some other elements too, such as oxygen and nitrogen. These can absorb certain wavelengths of light and change its color. For example, the blue-green color of the sky is due to oxygen molecules adsorbed onto the surface of the tungsten filament.
Tungsten filaments are very fragile. If they are not handled carefully they may break off inside the lamp housing. This could cause a dangerous situation if the bulb starts to burn out while you are using it because there will be no way to replace the broken piece.
Incandescent bulbs are widely used for their relatively simple design and low cost. However, they are energy inefficient and produce almost all types of radiation apart from ultraviolet: heat, radio waves, and visible light. They use up much of the electricity they consume and often need to be replaced after only 12-15 hours operation.
A light bulb is a device that generates light through the use of electricity. Light bulbs produce light by passing current via a small wire known as a filament. Typically, the filament is constructed of tungsten, a substance that generates light when power is carried through it. An electrical connection is made to the filament from another piece of wire called a lead wire. The lead wire connects to the outside world via a socket. When electricity flows through the filament, it heats it up and causes it to emit light.
Before the 1920s, all light bulbs used carbon filaments which burned out too soon. The next breakthrough came when Thomas Edison invented the incandescent lamp, which is still used today. The incandescent lamp does not burn out like its carbon-filament predecessor; instead, it becomes unusable after being turned off or left on for a long time. This is because electricity is needed to keep the filament hot so it can emit light, so these lamps need to be plugged in to work.
In 1927, General Electric introduced the fluorescent lamp, which has become the standard type of lamp used in offices, schools, and hospitals throughout the world. Like incandescent lamps, fluorescent lamps pass current through a thin tube filled with mercury vapor. But instead of a carbon filament, they have a gas plasma inside the tube that emits light when heated by the current.
When electricity is transferred through a light bulb, it generates light. A bulb is made up of both conductors and insulators. In a light bulb, the filament, which is a thin tungsten wire, conducts electricity. The glass envelope surrounding the filament is a protective insulator. Without the glass envelope, the heat from the filament would quickly break down plastic, causing it to melt and burn.
The term "conductor" means a material that allows electrons to flow through it. The electron flow creates a current. Conductors are important in circuits because they allow electricity to be transmitted from one place to another. There are two main types of conductors: resistive and reactive. Resistive conductors include metals like copper, silver, and gold. They are used when you want to make a connection that will not be broken under normal conditions. Reactive conductors include carbon black and white gas. They are used when you need a connection that will change color or shape depending on how much voltage is applied it. For example, you could use a colored tape to mark doorways into rooms where electricity is shut off to prevent injury due to excessive currents.
Conductors can also be divided into two groups based on whether they like electrons or not. Negative electrodes such as zinc, aluminum, and iron do not like electrons and so are called negative electrodes.