Alternating current is one of the forms of electric current. In this type of current, the direction of conduction of charges changes rapidly, causing the electrons to oscillate in opposite directions periodically. She is widely employed in electric power transmission and also in engineselectric. The production of this type of current is done by means of AC generators.
The study of alternating currents is particularly important for understanding the electrodynamic phenomenon known as electromagnetic induction, as well as one of its biggest applications, the transformers.
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What is alternating current?
Alternating current is a kind of electric current in which the sense in which the electrical charges flow is inverted periodically, unlike what happens with the chaindirect, in which electrons are conducted along a only sense.
This type of current is obtained from the electromagnetic induction in generatorsB.C, which are formed by a conducting loop designed to rotate in
highvelocity when inserted between magnets very strong. The rotation of the turn causes a change in the flowmagnetic through its area, which, in turn, induces the formation of an electrical current of variable polarity, whose frequency is related to the velocity where the rotation of the loop occurs.
THE chainalternating has great importance for the processes of electric power transmission and also for the operation of electric motors, such as those used in home appliances.
Despite having a sense, the electric current is the result of chaotic movement of a huge number of electrons, so it is considered a greatnessclimb.
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How does alternating current work?
Alternating current works by conducting electrons that oscillate around a fixed point at a frequency of 60 Hz (in Brazil). This means that, in one second, the electrons make a back-and-forth motion 60 times.
For electricity distribution, this type of electrical current is significantly more practical than direct current as it is much easier to change the Electric tension in alternating current than the voltage of direct current.
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Why do we use alternating current?
imagine that a hydroelectric plant produce electricity to one potency 10 MW electrical (10.106 W), that is, ten million watts. The potency (P = i. U) can be calculated by the product between the voltageelectric (U) and the electric current (i). All this energy could be transmitted in different ways, for example: 1 amp with a voltage of 10 million volts or even 10 million amps with an electrical voltage of 1 volt.
The first option ensures that such electrical power is transmitted with a voltagehigh, but with a relatively low electrical current. This makes the energy losses, because of the ANDmade joule, are drastically reduced.
The second option, in turn, would cause huge energy losses. That's why we use alternating electrical current so much: since lowering or raising the voltage of this type of electrical current only requires it to pass through a transformer, in practical terms, its use becomes more viable for electricity transmission.
Although alternating electrical current is present in pole wires, in power stations, in all types of motors and in most of the home appliances, many circuits make use of direct current, which can be obtained from the rectificationgiveschainalternating. To do this, the alternating electrical current must pass through an electrical circuit that uses just one of the oscillation directions of the electrons.
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How is alternating current generated?
THE alternating electric current is produced in AC generators, present in practically all types of power plants – hydroelectric plants,solar, wind,thermoelectric etc. AC generators make use of some source of kinetic energy external, such as the movement of water, wind, water vapor, among others, to promote the rotation of a large spiral conductive.
This spiral, which is found between large magnets, starts to suffer the action of a strengthelectromotiveinduced, which has its direction reversed according to the rotation of the loop. This electromotive force is simply a variable electrical voltage that causes alternating current to circulate. The physical principle behind the production of alternating current is known as Faraday's electromagnetic induction.
alternating current applications
The applications of electric current alternating current encompasses alternating current electric motors. In these motors, a magnet is set to rotate from the magnetic field produced by coils carried by alternating electrical currents.
In addition to motors, alternating currents are also used for the production of electromagnetic waves. Radio and television transmitting antennas, for example, are carried by alternating high-frequency currents to emit radio waves.
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Devices that work with alternating current
Check out a list of appliances that work with alternating current:
- Washing machine
- Vacuum Cleaner
- Fan
- Blender
- Food processor
- Compressor
By Rafael Hellerbrock
Physics teacher
