What is the transmission speed of electricity? How is electricity transmitted?

The transmission speed of electricity refers to the transmission speed of the electric field (some people say that the transmission speed of electrical signals is actually the same), not the moving speed of electrons. The speed at which the electrons in the wire can be moved several meters per second (macro speed) is already very high.
The electric field propagation speed is very fast. in a vacuum, the speed is about close to the speed of light.
. The transmission process of "electricity" is roughly like this: Before the circuit is connected, although there are free electrons in all parts of the metal wire, there is no electric field in the wire, and the whole wire is in the electrostatic equilibrium state, free electrons only perform irregular hot motion without directed motion, and of course there is no current in the wire. When the circuit is switched on, the electric field will transmit the information of the Field Source changes at a high-speed light, so that the electric field can be quickly established in the wires of the circuit, the electric field pushes the local free electrons for drift to form the current. It is a misunderstanding that after the switch is switched on, the Free Electron starts from the power supply and moves at the drifting speed. After the light is reached, the light will be on.

If there is an alternating current in the wire, there must be an Alternating Voltage at both ends of the wire, there will be an electric field that changes direction and size back and forth in the wire, the movement of electrons in this electric field is the reciprocating vibration on the wire. The amplitude is not large, but the frequency is very high. (It's like shaking your head back and forth !)

How is electric energy converted into other forms of energy? Generally, the current is produced by the electronic Directed Motion.
Conversion of heat energy: the collision between the energy and other factors (such as the proton) in the load during the movement, which leads to vibration, which is converted into heat energy although the Electronic quality is very small, the molecular kinetic energy is also relatively small, but the number of electrons is large. It is mainly related to the collision probability (which determines the size of the resistance) and converts it to light energy: the energy of the electron is transferred to some substances that are easy to transition, it is because these substances are in the excited state. According to the principle of lowest energy, the lower the energy, the more stable it is, then it must release energy and light energy to the outside world. If the regular motion of electrons appears in a ring, a magnetic field will be generated, and other loads will be driven based on the electromagnetic effect, such as the motor ...... And so on. Conversion to chemical energy: the charging power of the original battery supplements the yin and yang ions of the conductivity liquid, and breaks down the material on the electrode to realize energy conversion.

The larger the voltage, the stronger the electric field, and the greater the electron energy.

 

Generally, the electronic drift speed in other metal conductors is about 10-4 meters/second.
The reason for the metal conducting is that there are electrons that can freely move. Under the action of an electric field, the free electrons in the conductor generate an additional directed velocity against the direction of the electric field. The average value of the velocity is called the drifting speed.

Generally, the electronic drift speed in other metal conductors is about 10-4 meters/second. The average thermal velocity of free electrons in a metal is 105 Mbit/s. It can be seen that the directed drift speed of free electrons under the electric field is much less than the average thermal velocity.

Since the electronic drift speed in the metal conductor is so small, why do we usually say that the "electricity" transmission speed is very fast? Everyone knows that when the switch is switched on far away, the electric lights it controls will immediately turn on. If we estimate the electronic drift speed, it seems that after the switch is turned on, it will take a long time for the light to turn on.

In fact, this is not surprising. Generally, the propagation speed of "electricity" is not the electronic drift speed in the conductor, but the electric field transmission speed. The electric field propagation speed is very fast. in a vacuum, the speed is about 3 × 108 meters/second. The transmission process of "electricity" is roughly like this: Before the circuit is connected, although free electrons exist everywhere in the metal guide electronic line, there is no electric field in the wire, and the whole wire is in the electrostatic equilibrium state, free to only do a non-Rule hot movement without targeted movement, of course, there is no current in the wire. When the circuit is connected, the electric field will transmit the information of the Field Source changes at a speed of about 3 × 108 meters/second, so that the electric field can be quickly established in the wires of the circuit, the electric field pushes the local free electrons for drift to form the current. It is a misunderstanding that after the switch is switched on, the Free Electron starts from the power supply and moves at the drifting speed. After the light is reached, the light will be on.

We can use an image metaphor to illustrate the above principles. A team of students will enter the exhibition hall and form a straight line. The first team is at the door of the Exhibition Hall, and the end of the team is still on campus. The teachers of the command team are on campus, and the team is still waiting for a visit. When the instructor issued the command: "The tour begins !" The command is transmitted along the team at a speed of V (about 332 per second. The students who have heard the command will go forward at a much slower speed of V' (about 1 meter/second. When the voice is sent to the door of the exhibition hall, students standing at the door can visit the hall. Assume that the distance from the school to the exhibition hall is S meters. The command is sent to the entrance of the exhibition hall in t ≈ S/332 seconds. It takes T = S seconds for a person to walk from the school to the door of the exhibition hall. Here, the time from issuing the command to getting someone to enter the exhibition hall is t, not T. If the school is compared to a power supply, the exhibition hall is more effective than an electric appliance, and the instructor issues a command that is equivalent to a switch-on circuit, and the sound transmission speed is equivalent to the electric field propagation speed, then, the traveling speed is equivalent to the speed at which the electrons move along the wire. This process is similar to the situation where the electric field is transmitted along the wire at the speed of light after the power is switched on, and where the electric field is transmitted, the free electrons start to move in a direction. After the power is on, the electric field is transferred to the electric appliance for a very short time, so after the power is on, you can think that the current is immediately transferred to the electric appliance, so that it starts to work. The mechanical model we use can help students understand this problem visually and intuitively.