How fast is the electrical current?
You may have already noticed that when we press a switch, the lamp, or whatever electronic component is connected, turns on almost instantly. We can't even figure out how long it takes for a light to come on as soon as we hit the switch.
As a result of applying a Electric tension, the electric current arises. She is responsible for the operation of electronic devices and is the result of movement of the electrons in some directionpreferential. So far so good! But did you know that a mere turtle can move faster than the electrons in the wire?
The speed at which these particles move, called the drift speed or drag speed, is very small: in the order of a few millimeters per second (mm/s).
This speed is directlyproportional to the electrical current formed in the wire and inverselyproportional the density of free electrons (those that can be conducted), as well as the cross-sectional area of the wire and the charge of the electrons.
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But if electrons move so slowly within conductive media, what causes an almost instantaneous activation of electrical circuits?
What happens is, when we press the switch, the electric field is formed in the wire at the speed of light, about 300,000 km/s. This electric field drags electrons along the length of the wire almost instantly.
This means that if we installed a light bulb at the end of a 300,000 km long wire, it would take fence in asecond to light up after press the switch.
imagine a crowd of soldiers lined up. THE order in march is given by a whistle.Virtually all soldiers will hear the whistle and will start The march together. The first soldiers will arrive at the destination very quickly, but moving at speeds muchcasualties. On the wires, the order for the electrons to move is given by the fieldelectric, and she arrives at velocity gives light.
By Rafael Hellerbrock
Graduated in Physics
Would you like to reference this text in a school or academic work? Look:
HELERBROCK, Rafael. "What is the speed of the electric current?"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/qual-velocidade-corrente-eletrica.htm. Accessed on June 27, 2021.
Physics
Do you know what an electric field is? The electric field is vector, that is, at each point in space it has a specific module, direction and direction. The electric field is responsible for the emergence of forces of attraction and repulsion between electrical charges. Its units are Volts per meter or Newtons per coulomb.
