Why do light bulbs turn on? Why do lights shine?

An electric current passes through the filament, and in fact the directional movement of free electrons accelerates the average velocity of electrons, nuclei and other particles in the filament and increases the energy.

From a microscopic point of view, there may be electrons jumping from the ground state to the excited state, or from the excited state with less energy to the excited state with more energy, and the electrical energy is converted into internal energy, which increases the temperature of the filament.

The temperature is high to a certain level, generally around 1000 degrees Celsius, and it can emit light. At first, it is infrared, and when the temperature is high enough to emit visible light.

From a microscopic perspective, there may be electrons jumping from an excited state to a ground state, or from an excited state with more energy to an excited state with less energy. Unleash energy. Here electrical energy is converted into internal energy and light energy. To circulate the current, both the neutral and live wires must be connected.

Because after the power is applied, the resistance of the filament causes the electricity to do work on the filament. The filament temperature rises rapidly. The material of the filament determines that when the temperature of the filament reaches a certain level, it will produce light energy, which is why Edison experimented many times to find tungsten filament as filament.

Other materials are less efficient at converting light energy, like electric furnaces. So different materials have different uses. In order to protect the filament from being oxidized, the bulb is made sealed, and then filled with inert gas to protect the filament to prolong its life, in short, it is that after the temperature of the material rises to a certain level, it converts a part of the heat energy into light energy.

Reason:

In a high-pressure mercury lamp, many free electrons are produced by discharging, and the electrons are accelerated by electricity at a much faster rate than a bullet. When this electron collides with the mercury atom, it transfers energy to the mercury atom to excite it to reach an unstable high-energy state. In the same way, light is emitted when it spontaneously "falls" from the high-energy state and returns to the low-energy state.

Lamps appeared after humans learned to use fire, and have developed to the present day of incandescent lamps and discharge lamps. The history of human beings using lamps is very long, but it is still a matter of nearly one or two hundred years for people to figure out why lamps emit light.

Light is an electromagnetic wave. There are many waves in nature. Throwing a stone at the surface of the water will produce a circle of ripples, which are the water waves that can be seen directly by the eyes; Plucking a string creates audible sound waves in the air.

There is a lot of space in the airwaves, which we can neither see nor hear.

Light waves (wavelength meters to 4 10-5 meters) are also one of its members, but the wavelength is very short and the frequency of fluctuations is very high.

What kind of etc are you talking about, incandescent lamps are burning filaments, and LED lamps are diodes that generate heat.

What do you mean? Okay, oh lalalala, the demon thinks about swallowing and agreeing with the giant NV T

How fluorescent lamps work.

First, the structure of the fluorescent lamp.

The fluorescent lamp circuit consists of a lamp, a ballast, a starter, and a capacitor (see Figure 3-1), and the structure and working principle of each component are as follows.

1. Lamp tube The fluorescent tube is a glass tube, the inner wall is coated with a layer of phosphors (magnesium tungstate, calcium tungstate, zinc silicate, etc.), different phosphors can emit different colors of light. The lamp is filled with a thin inert gas (e.g. argon).

and mercury vapor, and the lamp has filaments made of tungsten at both ends, which are coated with oxides that tend to emit electrons when heated.

When the filament has an electric current passing through, the filament in the lamp emits electrons, which can also increase the temperature in the tube and evaporate the mercury. At this time, if enough voltage is added to both ends of the lamp, the argon gas in the tube will be ionized, so that the lamp will transition from argon discharge to mercury vapor discharge. When discharged, invisible ultraviolet light shines on the phosphor inside the tube wall, causing the lamp to emit visible light of various colors.

2. Ballast.

The ballast is an element connected in series with the fluorescent tube, which is actually an inductance coil wound around the core of the silicon steel sheet, and its inductive reactance value is very large. The functions of the ballast are: to limit the current of the lamp; Generate enough self-inductive electromotive force to make the lamp easy to discharge and ignite.

Ballasts generally have two heads, but some ballasts have an extra coil around in order to easily ignite when the voltage is insufficient, so there are also ballasts with four heads.

3. a starter.

The starter is a small glow tube filled with neon gas in a small glass tube and fitted with two electrodes. One of the electrodes is composed of two metals with different linear expansion coefficients (commonly called bimetal sheets), and when the two electrodes are separated, the bimetal sheets will bend due to heating when heated, so that the two electrodes will close automatically.

4. Capacitors.

Due to the large inductance of the ballast, the power factor of the fluorescent lamp circuit is very low, and it is left and right. In order to improve the power factor of the line, the user is required to connect an appropriately sized capacitor in parallel at the power supply.

If a lamp doesn't shine, is it still called a lamp?

The light bulb principle is the thermal effect of an electric current. When the current passes through the filament, it will heat up, and the object temperature will glow white when it reaches 1700 (reach the incandescent state), and when the actual incandescent lamp emits, the filament can reach 2400 2700.

The filament inside the bulb is tungsten filament, and its main component is tungsten. When the tungsten wire is energized, the temperature rises because the resistive electrical energy of the tungsten wire is converted into internal energy, which heats the tungsten wire. Generally, the metal will emit light after heating to a certain extent, this phenomenon is called the incandescent state, and when the filament temperature reaches the incandescent state when the power is on, the bulb will shine.

If the bulb lights up after it is powered on, this is normal, because after the power is on, the bulb can light up normally, because it has a battery.

The reason why the bulb glows after being energized is that when the positive and negative currents pass through a metal conductor with a very high resistance, it will glow and heat, so the bulb will glow.

When an incandescent lamp is energized, it will produce the thermal effect of an electric current, and it will glow when it heats up to a certain temperature.

Why do light bulbs light up when they are powered on? The bulb will light up when it is powered on, because it should be used Why does the bulb light light up after powering up? The light bulb will light up when it is powered on, because it applies this bulb Why does it light up when it is powered on?

The bulb glows when it is energized because it is applied to this. There is this business division where electric energy shines.

After the power is on, there is a current flowing through the filament resistance, the current does work through the filament resistance, the electrical energy is converted into internal energy, and a large amount of internal energy is released in the form of light, and the light bulb will shine.

It must have been made by him with some special Um-Hm materials, and then through the power system and then sparks, and when it is electrified, it can shine and shine.

Hit your light bulb back and forth, why does it light up after powering it on? I am a conductor of electricity after the bulb is energized, so the electricity is emitted through the conductor of the electrical circuit.

This is because, tungsten filament is converted into light energy by electrical energy, which is a chemical change that is irreversible.

Because there is a tungsten filament in the bulb, the tungsten filament will glow when it is energized, and the lamp will shine.

The small bulb will light up because there is an electric current passing through the filament. When the switch of the light bulb is turned on, an electric current will enter the bulb through the wire, and the temperature of the tungsten wire will increase when the current passes through the tungsten ruler. When its temperature rises to a certain level, it releases heat and emits light, so the bulb is on.

The small bulb will light up because there is an electric current passing through the filament. When the light bulb is turned on, an electric current will enter the bulb through the wire, and when the current passes through the tungsten wire, the temperature of the tungsten wire will rise. When its temperature rises to a certain level, it releases heat and emits light, so the bulb is on.

Electric lamps include incandescent bulbs, arc lamps, and fluorescent lamps.

The incandescent lamp is made by using the principle that high-temperature objects can emit light, and the tungsten filament is heated to a high temperature of thousands of degrees, and the tungsten filament emits light.

Arc lamps use the principle of arc light, which makes ionized high-temperature ions emit light.

Fluorescent lamps are made using the principle that phosphors can emit visible light when exposed to rays. Since it does not require high temperatures, it has a relatively high efficiency and is a promising light source.

When an electric current is passed through an electric lamp, the electrical energy is converted into heat energy, and it is the filament of the electric lamp that generates light that heats up, depending on what electric light it is. Are you sure you're asking about physics? You can send the online game version.

The principle of an incandescent lamp is very simple, that is, an electric current passes through the filament, produces a high temperature, reaches an incandescent state, excites the electrons in the outer shell of the nucleus, and produces light waves.

The principle of fluorescent lamp is that mercury vapor emits rays under the impact of high-voltage electricity and hits the phosphor of the lamp, which excites the phosphor to emit light. (If it's not on, it won't call the light) hehe!!

Because there is an electric current passing through it, it will light up. The current flows out of one end of the light bulb, generating heat in the metal part of the bulb, which causes the metal electrons to break free from the nucleus, so that the inner wall of the bulb continues to reciprocate, forming an electric current. There are a lot of small bubbles inside the light bulb, and there are also a large number of electrons in the small bubbles, and when the electrons in the small bubbles break free from the nucleus, they will continue to reciprocate on the inner wall of the small bubbles, forming an electric current, thus making the small bubbles glow.

So the light bulb will come on. The light bulb turns on and off because the temperature of the filament changes and the magnitude of the current also changes, so the light bulb will turn on. So the answer is:

When an electric current passes, the electrons break free from the nucleus and continue to reciprocate on the inner wall of the bulb, forming an electric current that makes the small bubbles glow.

The light bulb is something that we often see in our daily life, the light bulb's. It can be used in various places and is still used today, so everyone knows about the light bulb, so do you know what is the reason why the light bulb shines? I think many of your friends don't know much about Type I, so let's find out with me.

The filament of the light bulb is wound with a thin tungsten filament and is spiral-shaped. Generally, tungsten filament begins to glow when heated to 100. Tungsten filament can withstand 2300 2500 high heat.

In a light bulb made of glass, air is extracted, nitrogen, argon and other non-combustible gases are added, and then sealed, which is called an electric light bulb. When an electric current flows from an electric wire into a filament (tungsten filament), the resistance of the filament is quite large, resulting in high heat, and when the heat reaches a certain level, light is generated. Light bulbs are "glowing due to heat", so glowing bulbs are very hot, so never touch them.