We explain what electric current is and what electric intensity is. Also, the types of electric current and their effects.
what is electricity?
Electric current is called the flow ofelectric charge through a conductive material, due to the displacement of theelectrons that orbit the nucleus of the atoms that make up the driver.
This movement ofparticles starts once an external voltage is applied to the ends of the conductor, such as a battery, for example. This tension generates a electric field on electrons that, having a negative charge, are attracted to the positive terminal.
To be transmitted, the electric current requires materials that have a large quota of free electrons, that is, located in their last orbit around the nucleus and, therefore, capable of moving as they are less strongly attracted by 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 withelectricity They were in the eighteenth century and only had electrical charges obtained by rubbing (static) or induction. It took until 1800 to check the movement constant of an electric charge, when the Italian physicist Alessandro Volta invented the electric battery.
Intensity
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 rate of electric current can be compared with the amount of Water in a river, capable of moving loads and carrying out a quantity of work.
According to him 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 in common use, which gets its name from 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:
- DC (DC). Also called direct current (DC), it consists of a flow of electrical charges that does not change its direction in theweather, that is, it is produced based on a difference in electric 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 andBusiness. 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 calledphases. 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 allows to take advantage of the transmission of Energy at 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 endurance as it passes, resistance is generated (no material is perfect, some are more resistant 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 above all light. This is the working principle of light bulbs.
- Magnetic. Electric current generates magnetic fields, as in the case of electromagnets used in car scrap yards or electric compasses.
- Chemicals Electricity serves to cause changes in substances and catalyze (accelerate 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 oxide and the corrosion.
- Break chemical links to get pure substances (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.