what is Electricity?

What Does Corriente Eléctrica Mean

An electric current is called the flow of electric charge through a conductive material , due to the displacement of the electrons that orbit the nucleus of the atoms that make up the conductor.



This movement of particles begins once an external voltage is applied to the ends of the conductor, such as a battery , for example. This voltage generates an electric field on the electrons that, having a negative charge, are attracted towards the positive terminal.

To be transmitted, the electric current requires materials that have a large share of free electrons , that is, located in their last orbit around the nucleus and, therefore, capable of moving as they are less strongly attracted to it.

In this sense, a distinction can be made between conductive, semiconductor and insulating materials, according to their ability to transmit electric current (good, little and none, respectively).

The first experiments with electricity were in the eighteenth century and only had electrical charges obtained by friction (static) or induction. It took until 1800 to see the constant motion of an electric charge, when the Italian physicist Alessandro Volta invented the electric battery.

See also: Magnetism


The intensity is the speed of displacement of the charges on the material.

This is the name given to the flow of electric current , that is, the amount of electric charge that passes through a conductive material per unit of time. The flow of electrical current can be compared to the amount of water in a river, capable of moving charges and carrying out a quantity of work.

According to the International System (SI), this intensity is normally measured in Coulombs per second (C / s) , which is equivalent to one ampere (A), a basic unit in the field of electricity and commonly used, which gets its name by the French physicist André-Marie Ampère. A galvanometer or ammeter is used to measure the intensity of the electric current.

Types of electric current

Depending on its nature, electric current can be of several types:

  • Direct current (DC). Also called direct current (DC), it consists of a flow of electrical charges that does not change its direction in time , that is, it is produced based on a difference in electrical potential ( voltage ) whose highest and lowest potential terminals are not interchangeable. In other words, its sense of circulation is always the same.
  • Alternating current (AC). Unlike the continuous one, it is an electric current whose sense and direction varies cyclically. This current is mathematically described by sine waves and in energy terms it is much more efficient than direct current, which is why it is received by homes and businesses . It was invented by Nikola Tesla in the late 19th century.
  • Triphasic current. Three-phase current is the most commonly generated form of electricity and consists of three alternating currents of identical frequency and amplitude, given in a certain order and called phases . This system, also a product of Tesla's experiments, is highly efficient and, therefore, the most popular on the planet.
  • Single phase current. It is obtained by taking a single phase of the three-phase current and a neutral wire, which makes it possible to take advantage of the transmission of energy in a low voltage (230 volts). Although it is used in many countries because it is sufficient to operate electrical appliances, many other appliances that require high electrical power do not operate with it.

Electric current's effects

When the electrical resistance of a conductive wire is very small, it generates heat and light.

Electric current offers humanity an enormous number of practical uses:

  • Caloric. When heat is transmitted through a material that offers resistance to its passage, a resistance is generated (no material is perfect, some have more resistance than others). This resistance dissipates heat that can be used to heat spaces, cook, etc.
  • Luminous. When the electrical resistance of a conductive wire is very low, a large number of electrons circulate through it, generating heat and especially light . This is the working principle of light bulbs.
  • Magnetic. Electric current generates magnetic fields, as in the case of electromagnets used in automobile scrap yards or in electric compasses.
  • Chemicals Electricity is used to cause changes in substances and catalyze (speed up or make more effective) certain chemical reactions . This allows mechanisms such as electrolysis, the process that separates the elements of a compound by means of electricity and that is useful for, for example:

    • Protect metals from rust and corrosion .
    • Breaking chemical bonds to obtain pure substances (such as oxygen and hydrogen from water ).
    • Melt certain metals (for gold plating, for example).
  • Mechanics. Electricity provides the energy necessary to activate devices that carry out a certain mechanical work, such as motors that generate movement , traction or speed.
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