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Each of us still remembers from the school course that electricity– directed motion of electric particles under the influence of an electric field. Such particles can be electrons, ions, etc. Nevertheless, despite the simple formulation, many admit that they do not fully know what electricity is, what it consists of, and, in general, why all electrical engineering works.

To begin with, it is worth turning to the history of this issue. The term "electricity" first appeared in 1600 in the writings of the English naturalist William Gilbert. He studied the magnetic properties of bodies, touching upon the magnetic poles of our planet in his writings, and described several experiments with electrified bodies that he himself conducted.

You can read about this in his work "On the magnet, magnetic bodies and the big magnet - the Earth." The main conclusion of his work was that many bodies and substances can be electrified, which is why they have magnetic properties. His research was applied in the creation of compasses and in many other areas.

But William Gilbert is by no means the first to discover such properties of bodies, he is simply the first to study them. As early as the 7th century BC, the Greek philosopher Thales noticed that amber, rubbed against wool, acquires amazing properties He starts to attract things towards him. Knowledge about electricity remained at this level for several centuries.

This situation remained until the 17th and 18th centuries. This time can be called the dawn of the science of electricity. William Gilbert was the first, after him many other scientists from all over the world dealt with this issue: Franklin, Coulomb, Galvani, Volt, Faraday, Ampere, as well as the Russian scientist Vasily Petrov, who discovered the voltaic arc in 1802.

All these scientists made outstanding discoveries in the field of electricity, which laid the foundation for the subsequent study of this issue. Since then, electricity has ceased to be something mysterious, but, despite the great achievements in this matter, there were still a lot of mysteries and ambiguities.

The most important question, as always, was: how to use all these achievements for the benefit of mankind? Because, despite significant advances in the field of studying the nature of electricity, it was still far from being put into practice. It still seemed something mysterious and unattainable.

This can be compared to how scientists around the world are now studying space and the nearest planet Mars. A lot of information has already been received, it has been established that it is possible to fly to it and even land on the surface, etc., but there is still a lot of work to actually achieve such goals.

Speaking about the nature of electricity, it is impossible not to mention its most important manifestation in nature. After all, it was there that a person encountered it for the first time, it was in nature that he began to study it and tried to understand it, and made the first attempts to tame it and benefit for himself.

Of course, when we talk about the natural manifestation of electricity, lightning comes to everyone's mind. Although at first it was still not clear what they were, and their electrical nature was established only in the 18th century, when an active study of this phenomenon began in conjunction with previously acquired knowledge. By the way, according to one of the versions, it was lightning that influenced the appearance of life on Earth, because without them the synthesis of amino acids would not have begun.

There is also electricity inside the human body, without it the nervous system would not work, and a nerve impulse occurs as a result of a short-term voltage. In the oceans and seas there are many fish that use electricity for hunting and protection. For example, an electric eel can reach a voltage of up to 500 volts, while a stingray has a discharge power of about 0.5 kilowatts.

Some types of fish create a lung around them. electric field, which is distorted by all objects in the water, so they can easily navigate even in very muddy water and have advantages over other fish.

So since ancient times, electricity has often been found in nature, without it the appearance of man would not have been possible, and many animals use it to find food. For the first time, a person encountered these phenomena in a natural manifestation, and this prompted him to further study.

Practical application of electricity

Over time, man continued to accumulate knowledge about this amazing phenomenon. Electricity reluctantly revealed its secrets to him. Around the middle of the 19th century, electricity began to penetrate the life of human civilization. It was first used for lighting when the light bulb was invented. With its help, they began to transmit information over long distances: radio, television, telegraph, etc. appeared.

But special attention deserves the appearance of various mechanisms and devices that were set in motion by electricity. To this day, it is difficult to imagine the operation of any device or machine without electricity. All Appliances in a modern house works only on electricity.

Achievements in the field of generating electricity were also a big breakthrough, so more and more powerful power plants and generators began to be created; storage batteries were invented.

Electricity has helped to make many other discoveries, it helps in science and in the study of new issues. Some technologies work on the basis of electrical properties, they are used in medicine, industry and, of course, in everyday life.

So what is electricity?

No matter how strange it may sound, but the widespread use of electricity does not make it any more understandable. Everyone knows the basic principles of work, safety precautions and everything. Some people admit that they have no idea what electricity is at all, others do not know why it works this way and not otherwise, others do not understand the difference between voltage, power and resistance, and there are many similar examples.

The easiest way to understand the nature of electricity is at the molecular level. All substances are made up of molecules, all molecules are made up of atoms, and every atom is made up of a nucleus around which electrons revolve.

Electrons are the "carriers" of electricity, and electric current is a continuous movement a large number such electrons.

Electrical engineering has reached great success during its development, however, the study of its nature still requires great efforts, because many problems still remain unsolved or the solutions that have been found are not as effective as they could be. At the heart of everything is the transformation of forces. Today, electrical energy can be easily converted into light energy, using it for lighting, it can be used to move various mechanisms, and so on.

Another feature and main advantage of electrical energy over other types of energy is its prevalence, unlimitedness in space. Electricity continuously accompanies a person in all spheres of his life, is considered an example of evolution and outlook on the future, and the process of technological development is continuously connected with the development of science and new achievements.

This expands the capabilities of a person, improves his tools and guarantees him constant development and movement forward into the future, and many tasks cease to seem impossible over time.


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Electricity is an extremely useful form of energy. It easily transforms into other forms, such as light or heat. It can be easily transferred by wire. The word "electricity" comes from the Greek word "electron" - "amber". When rubbed, amber acquires an electric charge and begins to attract pieces of paper. Static electricity has been known since ancient times, but only 200 years ago people learned how to create an electric current. Electricity brings us heat and light, it runs a variety of machines, including computers and calculators.

What is electricity

Electricity exists thanks to particles that have electric charges. There are charges in every substance - after all, atomic nuclei have a positive charge, and negatively charged electrons circulate around them (see the article ""). Normally, an atom is electrically neutral, but when it gives up its electrons to other atoms, it acquires a positive charge, and the atom that has received additional electrons is negatively charged. it is possible to give some objects an electric charge, called static electricity. If rubbed Balloon With a woolen jumper, some of the electrons will pass from the jumper to the ball, and it will acquire a positive charge. The jumper is now positively charged and the ball sticks to it as opposite charges attract each other. Electric forces act between charged bodies, and bodies with opposite (positive and negative) charges attract each other. Objects with the same charge, on the other hand, repel each other. In a Van de Graaff generator, when a rubber band is rubbed against a roller, a significant static charge is generated. If a person touches the dome, his hair will stand on end.

In some substances, for example, in, electrons can move freely. When something sets them in motion, there is a flow of electrical charges called current. conductors are substances that can conduct electricity. If a substance does not conduct electricity, it is called insulator. Wood and plastic are insulators. For insulation purposes, the electrical switch is placed in a plastic case. Wires are usually made of copper and covered with plastic for insulation.

Static electricity was first discovered by the ancient Greeks over 2,000 years ago. Now static electricity is used to obtain photocopies, faxes, printouts on laser printers. The laser beam reflected by the mirror creates on the drum laser printer point static charges. The toner is attracted to these points and pressed against the paper.

Lightning

Lightning is caused by static electricity that builds up in thundercloud as a result of the friction of water droplets and ice crystals against each other. When rubbing against each other and against the air, drops and ice crystals acquire a charge. Positively charged droplets collect at the top of the cloud, and a negative charge accumulates at the bottom. A large spark, called the lightning leader, rushes to the ground, to a point with an opposite charge. Before the appearance of the leader, the potential difference in the upper and lower regions of the cloud can be up to 100 million volts. The leader causes a response discharge, rushing in the same way from to the cloud. inside this discharge is five times hotter than the surface of the Sun - it heats up to 33,000 ° C. The air heated by lightning discharges expands rapidly, creating an air wave. We perceive it as thunder.

Electricity

Electric current is a flow of charged particles moving from a region of high electric potential to a region of low potential. Particles results in a potential difference, which is measured in volts. For current to flow between two points, a continuous "road" is needed - a circuit. There is a potential difference between the two poles of a battery. If you connect them in a circuit, there will be a current. The current strength depends on the potential difference and the resistance of the circuit elements. All substances, even conductors, offer some resistance to current and weaken it. The unit of current is named ampere(A) in honor of the French scientist André-Marie Ampère (1775 - 1836).

Different devices need different current. Electrical appliances, such as light bulbs, convert electrical current into other forms of energy, into heat and light. These devices can be connected in a circuit in two ways: in series and in parallel. In a series circuit, current flows through all the components in turn. If one of the components burns out, the circuit opens and the current is lost. In a parallel circuit, current flows in several ways. If one component of the circuit fails, the current continues to flow through the other branch.

Batteries

A battery is a store of chemical energy that can be turned into electricity. The most typical battery used in everyday life is called dry element. In it is electrolyte(substance containing charged particles capable of moving). As a result, opposite charges separate and move towards opposite poles of the battery. Scientists have discovered that the fluid in the body of a dead frog acts as an electrolyte and conducts electricity.

Alessandro Volta (1745-1827) created the world's first battery from a stack of acid-soaked and acid-soaked cardboard disks with zinc and copper disks sandwiched between them. The unit voltage is named after him. volt. A 1.5 V battery is called a cell. Large batteries are made up of several cells. A 9 V battery contains 6 cells. Dry call primary elements. When the electrolyte components are used up, the life of the battery ends. secondary elements These are batteries that can be recharged. A car battery is a secondary element. It is recharged by the current generated inside the machine. The solar battery converts the sun's energy into electrical energy. When illuminated sunlight silicon layers, the electrons in them begin to move, creating a potential difference between the layers.

Electricity in our house

The mains voltage in some countries is 240 V, in others 110 V. This is a high voltage, and electric shock can be fatal. Parallel circuits bring electricity to various parts of the house. All electronic devices are equipped with fuses. Inside them are very thin wires that melt and break the circuit if the current is too high. Each branch circuit usually has three wires: live and ground. Current flows through the first two, and the ground wire is needed for safety. It will divert electric current to the ground in the event of an insulation breakdown. When a plug is plugged into an outlet, the connectors connect to a live wire and a neutral wire, completing the circuit. In some countries, plugs with two connectors are used, without grounding (see fig.).

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What is electricity?

Electricity is a collection physical phenomena associated with the presence of an electric charge. Although initially electricity was considered as a phenomenon separate from magnetism, but with the development of Maxwell's equations, both of these phenomena were recognized as part of a single phenomenon: electromagnetism. Various common phenomena are associated with electricity, such as lightning, static electricity, electrical heating, electrical discharges, and many others. In addition, electricity is at the heart of many modern technologies.

The presence of an electric charge, which can be either positive or negative, generates an electric field. On the other hand, the movement of electric charges, which is called electric current, creates a magnetic field.

When a charge is placed at a point with a non-zero electric field, a force acts on it. The magnitude of this force is determined by Coulomb's law. Thus, if this charge were moved, the electric field would do the work of moving (braking) the electric charge. Thus, we can talk about the electric potential at a certain point in space, equal to the work performed by an external agent when transferring a unit of positive charge from an arbitrarily chosen reference point to this point without any acceleration and, as a rule, measured in volts.

In electrical engineering, electricity is used to:

  • supplying electricity to where electric current is used to power equipment;
  • in electronics dealing with electrical circuits that include active electrical components such as vacuum tubes, transistors, diodes, and integrated circuits, and their associated passive elements.

Electrical phenomena have been studied since ancient times, although progress in theoretical understanding began in the 17th and XVIII centuries. Even then practical use Electricity was a rarity, and engineers were able to use it for industrial and residential purposes only at the end of the 19th century. The rapid expansion of electrical technology at this time transformed industry and society. The versatility of electricity lies in the fact that it can be used in an almost limitless number of industries such as transportation, heating, lighting, communications and computing. Electricity is now the backbone of modern industrial society.

History of electricity

Long before there was any knowledge of electricity, people already knew about electric shocks to electric fish. Ancient Egyptian texts dating back to 2750 BC. BC, they called these fish "Thunderers of the Nile" and described them as "protectors" of all other fish. Evidence of electric fish appears again thousands of years later from ancient Greek, Roman and Arab naturalists and doctors. Several ancient writers, such as Pliny the Elder and Scribonius Largus, testify to numbness as an effect of electric shocks produced by catfish and electric rays, and they also knew that such shocks could be transmitted through conductive objects. Patients suffering from diseases such as gout or headache were prescribed to touch such fish in the hope that a powerful electric shock could cure them. It is possible that the earliest and closest approximation to the discovery of the identity of lightning and electricity from any other source was made by the Arabs, who until the 15th century in the language applied the word for lightning (raad) to electric rays.

The ancient cultures of the Mediterranean knew that if certain objects, such as amber sticks, were rubbed with cat fur, it would attract lighter objects, such as feathers. Thales of Miletus made a number of observations of static electricity around 600 BC, from which he deduced that friction was needed to make amber capable of attracting objects, unlike minerals such as magnetite, which did not need friction. . Thales was wrong in believing that the attraction of amber was due to the magnetic effect, but later science proved the connection between magnetism and electricity. According to a controversial theory based on the discovery of the Baghdad battery in 1936 that resembles a galvanic cell, although it is not clear if the artifact was electrical in nature, the Parthians may have been aware of electroplating.

Electricity continued to arouse nothing more than intellectual curiosity for millennia until 1600, when the English scientist William Gilbert made a thorough study of electricity and magnetism, and distinguished the "magnetite" effect from the static electricity produced by rubbing amber. He coined the new Latin word electricus ("amber" or "like amber", from ἤλεκτρον, Elektron, from Greek: "amber") to denote the property of objects to attract small objects after rubbing. This linguistic association has given rise to English words"electric" and "electricity", which first appeared in print in Thomas Browne's "Pseudodoxia Epidemica" in 1646.

Further work was carried out by Otto von Guericke, Robert Boyle, Stephen Gray and Charles Francois Dufay. In the 18th century, Benjamin Franklin did extensive research into electricity, selling his holdings to finance his work. In June 1752, he is known to have attached a metal key to the bottom of the thread. kite and launched a kite into the stormy sky. The sequence of sparks jumping from the key to the back of the hand showed that the lightning was indeed electrical in nature. He also explained the seemingly paradoxical behavior of the Leyden jar as a device for storing a large amount of electrical charge in terms of electricity, consisting of positive and negative charges.

In 1791, Luigi Galvani announced his discovery of bioelectromagnetism, demonstrating that electricity is the means by which neurons transmit signals to muscles. The Alessandro Volta battery or galvanic pole of the 1800s was made from alternating layers of zinc and copper. For scientists, it was a more reliable source of electrical energy than the electrostatic machines used in the past. The understanding of electromagnetism as the unity of electrical and magnetic phenomena was due to Oersted and André-Marie Ampère in 1819-1820. Michael Faraday invented the electric motor in 1821 and Georg Ohm mathematically analyzed the electrical circuit in 1827. Electricity and magnetism (and light) were definitively connected by James Maxwell, in particular in his work "On Physical Lines of Force" in 1861 and 1862.

While at the beginning of the 19th century the world witnessed rapid progress in the science of electricity, at the end of the 19th century the greatest progress occurred in the field of electrical engineering. With the help of people like Alexander Graham Bell, Otto Titus Blaty, Thomas Edison, Galileo Ferraris, Oliver Heaviside, Anjos Istvan Jedlik, William Thomson, 1st Baron Kelvin, Charles Algernon Parsons, Werner von Siemens, Joseph Wilson Swan, Reginald Fessenden , Nikola Tesla and George Westinghouse, electricity has evolved from a scientific curiosity into an indispensable tool for modern life, becoming the driving force behind the second industrial revolution.

In 1887, Heinrich Hertz discovered that electrodes lit with ultraviolet light produced electrical sparks more easily than unlit ones. In 1905, Albert Einstein published a paper explaining the experimental evidence for the photoelectric effect as a result of the transfer of light energy in discrete quantized packets that excite electrons. This discovery led to the quantum revolution. Einstein was awarded Nobel Prize in physics in 1921 for "the discovery of the law of the photoelectric effect." The photovoltaic effect is also used in photovoltaic cells such as those found in solar panels, and this is often used to generate electricity for commercial purposes.

The first semiconductor device was the "cat's whisker" detector, which was first used in radio receivers in the 1900s. The whisker-like wire is brought into light contact with a solid crystal (eg, a germanium crystal) in order to detect a radio signal through a contact-transition effect. In a semiconductor node, current is applied to semiconductor elements and connections designed specifically for switching and amplifying current. Electric current can be represented in two forms: in the form of negatively charged electrons, as well as positively charged electron vacancies (unfilled electrons in places in a semiconductor atom), called holes. These charges and holes are understood from the standpoint of quantum physics. The building material is most often a crystalline semiconductor.

The development of semiconductor devices began with the invention of the transistor in 1947. Common semiconductor devices are transistors, microprocessor chips, and RAM chips. A specialized type of memory called flash memory is used in USB flash drives, and more recently, mechanically rotating hard disk drives have also been replaced by solid-state drives. Semiconductor devices became common in the 1950s and 1960s, during the transition from vacuum tubes to semiconductor diodes, transistors, integrated circuits (ICs), and light-emitting diodes (LEDs).

Basic concepts of electricity

Electric charge

The presence of a charge generates an electrostatic force: the charges exert a force on each other, this effect was known in antiquity, although it was not then understood. A light ball suspended on a string can be charged by touching it with a glass rod, which itself was previously charged by rubbing against a cloth. A similar ball charged by the same glass rod will repel the first: the charge causes the two balls to separate from each other. Two balls that are charged from a rubbed amber rod also repel each other. However, if one ball is charged from a glass rod and the other from an amber rod, then both balls begin to attract each other. These phenomena were investigated at the end of the eighteenth century by Charles Augustin de Coulomb, who concluded that the charge appears in two opposite forms. This discovery led to a well-known axiom: similarly charged objects repel, and oppositely charged objects attract.

The force acts on the charged particles themselves, hence the charge tends to spread as uniformly as possible over the conducting surface. The magnitude of the electromagnetic force, whether attractive or repulsive, is determined by Coulomb's law, which states that the electrostatic force is proportional to the product of the charges and inversely proportional to the square of the distance between them. The electromagnetic force is very strong, second only to strong interaction, but unlike the latter, it acts at any distance. Compared to the much weaker gravitational force, the electromagnetic force pushes two electrons 1042 times more than the gravitational force pulls them.

The study showed that the source of the charge is certain types of subatomic particles that have the property of an electric charge. The electric charge generates and interacts with the electromagnetic force, which is one of the four fundamental forces of nature. The most well-known carriers of electric charge are the electron and the proton. The experiment showed that the charge is a conserved quantity, that is, the total charge inside an isolated system will always remain constant regardless of any changes that occur within this system. In a system, charge can be transferred between bodies either by direct contact or by transfer through a conductive material such as a wire. The informal term "static electricity" means the net presence of a charge (or "imbalance" of charges) on a body, usually caused by dissimilar materials being rubbed against each other, transferring charge from one to the other.

The charges of electrons and protons are opposite in sign, therefore, the total charge can be either positive or negative. By convention, the charge carried by electrons is considered negative, and that carried by protons is positive, following the tradition established by the work of Benjamin Franklin. The amount of charge (the amount of electricity) is usually denoted by the symbol Q and is expressed in coulombs; each electron carries the same charge, approximately -1.6022 × 10-19 coulombs. The proton has a charge equal in value and opposite in sign, and thus +1.6022 × 10-19 Coulomb. Not only matter has a charge, but also antimatter, each antiparticle carries an equal charge, but opposite in sign to the charge of its corresponding particle.

Charge can be measured in several ways: the early gold-leaf electroscope, which, although still used for training demonstrations, is now replaced by an electronic electrometer.

Electricity

The movement of electric charges is called electric current, its intensity is usually measured in amperes. The current can be created by any moving charged particles; most often these are electrons, but in principle any charge set in motion is a current.

By historical convention, positive current is determined by the direction of movement of positive charges flowing from the more positive part of the circuit to the more negative part. The current defined in this way is called the conditional current. One of the most well-known form of current is the movement of negatively charged electrons through a circuit, and thus the positive direction of the current is oriented in the opposite direction to the movement of the electrons. However, depending on the conditions, an electric current can consist of a stream of charged particles moving in any direction, and even in both directions at the same time. The convention that the positive direction of the current is the direction of movement of positive charges is widely used to simplify this situation.

The process by which an electric current passes through a material is called electrical conduction, and its nature varies depending on which charged particles conduct it and on the material through which they move. Examples of electrical currents include metallic conduction, carried out by the flow of electrons through a conductor such as metal, and electrolysis, carried out by the flow of ions (charged atoms) through a liquid or plasma, as in electrical sparks. While the particles themselves can move very slowly, sometimes with average speed drifting only a fraction of a millimeter per second, the electric field that propels them travels at close to the speed of light, allowing electrical signals to travel quickly through the wires.

The current causes a number of observable effects that have historically been a sign of its presence. The possibility of water decomposition under the influence of current from a galvanic column was discovered by Nicholson and Carlisle in 1800. This process is now called electrolysis. Their work was greatly expanded by Michael Faraday in 1833. The current flowing through the resistance causes localized heating. This effect was described mathematically by James Joule in 1840. One of the most important discoveries regarding current was made by accident by Oersted in 1820, when, while preparing a lecture, he discovered that current flowing through a wire caused the needle of a magnetic compass to turn. So he discovered electromagnetism, the fundamental interaction between electricity and magnetism. The level of electromagnetic emissions generated by an electric arc is high enough to produce electromagnetic interference that can damage the operation of adjacent equipment. He discovered electromagnetism, the fundamental interaction between electricity and magnetism. The level of electromagnetic emissions generated by an electric arc is high enough to produce electromagnetic interference that may interfere with nearby equipment.

For technical or domestic applications, current is often characterized as either direct (DC) or alternating (AC). These terms refer to how current changes over time. The direct current produced by a battery, for example, and required by most electronic devices, is a unidirectional flow from the positive potential of the circuit to the negative. If this flow, which happens more often, is carried by electrons, they will move in the opposite direction. Alternating current is any current that continuously changes direction, it is almost always in the form of a sinusoid. The alternating current pulsates back and forth within the conductor without moving the charge any finite distance in a long period of time. The time-averaged value of the alternating current is zero, but it delivers energy first in one direction and then in the opposite direction. Alternating current depends on electrical properties that do not manifest themselves in a stationary mode of direct current, for example, on inductance and capacitance. These properties, however, may come into play when the circuit is subjected to transients, such as during initial power up.

Electric field

The concept of an electric field was introduced by Michael Faraday. An electric field is created by a charged body in the space that surrounds the body and results in a force acting on any other charges located in the field. An electric field acts between two charges similar to a gravitational field between two masses, and also extends to infinity and is inversely proportional to the square of the distance between the bodies. However, there is a significant difference. Gravity always attracts, causing two masses to join together, while an electric field can result in either attraction or repulsion. Since large bodies such as planets as a whole have zero net charge, their electric field at a distance is usually zero. Thus, gravity is the dominant force at large distances in the universe, despite the fact that it itself is much weaker.

The electric field, as a rule, differs at different points in space, and its strength at any point is defined as the force (per unit charge) that a motionless, negligible charge will experience if it is placed at that point. The abstract charge, called "test charge", must be of negligible value so that its own electric field disturbing the main field can be neglected, and must also be stationary (immobile) to prevent the influence of magnetic fields. Since an electric field is defined in terms of force, and force is a vector, then an electric field is also a vector, having both magnitude and direction. More specifically, the electric field is a vector field.

The doctrine of electric fields created by stationary charges is called electrostatics. The field can be visualized using a set of imaginary lines, the direction of which at any point in space coincides with the direction of the field. This concept was introduced by Faraday, and the term "lines of force" is still occasionally encountered. Field lines are the paths along which a point positive charge will move under the influence of a field. They are, however, an abstract, not a physical object, and the field permeates all the intermediate space between the lines. Field lines emanating from stationary charges have several key properties: first, they start on positive charges and end on negative charges; secondly, they must enter any ideal conductor at right angles (normal), and thirdly, they never intersect and close on themselves.

A hollow conducting body contains all of its charge on its outer surface. Therefore, the field is equal to zero in all places inside the body. The Faraday cage works on this principle - a metal shell that isolates its internal space from external electrical influences.

The principles of electrostatics are important in the design of elements of high-voltage equipment. There is a finite limit to the electric field strength that can be sustained by any material. Above this value, an electrical breakdown occurs, which causes an electric arc between the charged parts. For example, in air, electrical breakdown occurs at small gaps with an electric field strength exceeding 30 kV per centimeter. With an increase in the gap, the ultimate breakdown strength decreases to approximately 1 kV per centimeter. The most notable such natural phenomenon is lightning. It occurs when charges are separated in the clouds by ascending columns of air, and the electric field in the air begins to exceed the breakdown value. The voltage of a large thundercloud can reach 100 MV and have a discharge energy value of 250 kWh.

The magnitude of the field strength is strongly influenced by nearby conductive objects, and the strength is especially high when the field has to bend around pointed objects. This principle is used in lightning rods, whose sharp spiers force lightning to discharge into them rather than into the buildings they protect.

Electrical potential

The concept of electric potential is closely related to the electric field. A small charge placed in an electric field experiences a force, and in order to move the charge against this force, work is required. The electric potential at any point is defined as the energy required to move a unit test charge extremely slowly from infinity to that point. Potential is usually measured in volts, and a potential of one volt is the potential at which one joule of work must be expended to move one coulomb of charge from infinity. This formal definition of potential is of little practical use, and more useful is the concept of electrical potential difference, that is, the energy required to move a unit of charge between two given points. The electric field has one feature, it is conservative, which means that the path traveled by the test charge does not matter: the passage of all possible paths between two given points will always take the same energy, and thus there is a single value of the difference potentials between two positions. The volt has become so firmly established as a unit of measurement and description of the difference in electrical potential that the term voltage is used widely and everyday.

For practical purposes, it is useful to define a common reference point against which potentials can be expressed and compared. Although it can be at infinity, it is much more practical to use the Earth itself as the zero potential, which is assumed to have the same potential in all places. This reference point, of course, is referred to as "ground" (ground). The earth is an infinite source of equal amounts of positive and negative charges and is therefore electrically neutral and unchargeable.

Electric potential is a scalar quantity, that is, it only has a value and no direction. It can be thought of as analogous to height: just as a released object will fall due to the height difference caused by the gravitational field, so the charge will "fall" due to the voltage caused by the electric field. Just as maps represent terrain by means of contour lines connecting points of equal height, a set of lines connecting points of equal potential (known as equipotentials) can be drawn around an electrostatically charged object. Equipotentials intersect all lines of force at right angles. They must also lie parallel to the surface of the conductor, otherwise a force will be produced that moves charge carriers along the equipotential surface of the conductor.

An electric field is formally defined as the force exerted per unit charge, but the concept of potential provides a more useful and equivalent definition: an electric field is a local electric potential gradient. As a rule, it is expressed in volts per meter, and the direction of the field vector is the line of greatest potential change, that is, in the direction of the nearest location of another equipotential.

Electromagnets

Oersted's discovery in 1821 of the fact that a magnetic field exists around all sides of a wire carrying an electric current showed that there was a direct relationship between electricity and magnetism. Moreover, the interaction seemed different from gravitational and electrostatic forces, two forces of nature then known. The force acted on the compass needle, not towards or away from the current wire, but at right angles to it. In slightly obscure words "electrical conflict has a rotating behavior" Oersted expressed his observation. This force also depended on the direction of the current, for if the current changed direction, then the magnetic force changed it too.

Oersted did not fully understand his discovery, but the effect he observed was mutual: the current exerts a force on the magnet, and the magnetic field exerts a force on the current. The phenomenon was further studied by Ampère, who discovered that two parallel current-carrying wires exert a force on each other: two wires carrying currents in the same direction attract each other, while the wires containing currents in opposite directions from each other repel each other. This interaction occurs through the magnetic field that each current creates, and based on this phenomenon, the current unit is determined - Ampere in international system units.

This relationship between magnetic fields and currents is extremely important because it led to Michael Faraday's invention of the electric motor in 1821. His unipolar motor consisted of a permanent magnet placed in a vessel of mercury. The current was passed through a wire suspended on a hinged suspension above a magnet and immersed in mercury. The magnet exerted a tangential force on the wire, which caused the latter to revolve around the magnet for as long as current was maintained in the wire.

An experiment done by Faraday in 1831 showed that a wire moving perpendicular to a magnetic field created a potential difference at the ends. Further analysis of this process, known as electromagnetic induction, allowed him to formulate the principle, now known as Faraday's law of induction, that the potential difference induced in a closed circuit is proportional to the rate of change magnetic flux penetrating contour. The development of this discovery allowed Faraday to invent the first electrical generator, in 1831, which converts the mechanical energy of a rotating copper disk into electrical energy. The Faraday disk was inefficient and was not used as a practical generator, but it showed the possibility of generating electricity using magnetism, and this possibility was taken up by those who followed his developments.

The ability of chemical reactions to produce electricity, and, inversely, the ability of electricity to produce chemical reactions has a wide range of applications.

Electrochemistry has always been an important part of the study of electricity. From the original invention of the voltaic column, galvanic cells have evolved into a wide variety of types of batteries, galvanic and electrolytic cells. Aluminum is obtained from huge quantities by electrolysis, and many portable electronic devices use rechargeable power sources.

Electrical circuits

An electrical circuit is a connection of electrical components in such a way that an electric charge forced to pass along a closed path (circuit) usually performs a number of some useful tasks.

Components in an electrical circuit can take various forms acting as elements such as resistors, capacitors, switches, transformers and electronic components. Electronic circuits contain active components, such as semiconductors, which typically operate in a non-linear manner and require complex analysis to be applied to them. The simplest electrical components are what are called passive and linear: although they can temporarily store energy, they do not contain any energy sources and operate in a linear fashion.

A resistor is perhaps the simplest of the passive circuit elements: as its name suggests, it resists the current flowing through it, dissipating electrical energy as heat. Resistance is a consequence of the movement of charge through a conductor: in metals, for example, resistance is primarily due to collisions of electrons and ions. Ohm's law is the basic law of circuit theory and states that the current passing through a resistance is directly proportional to the potential difference across it. The resistance of most materials is relatively constant over a wide range of temperatures and currents; materials that meet these conditions are known as "ohmic". The ohm is a unit of resistance named after Georg Ohm and is denoted by the Greek letter Ω. 1 ohm is a resistance that creates a potential difference of one volt when a current of one ampere is passed through it.

The capacitor is an upgrade of the Leyden jar and is a device that can store charge and thereby accumulate electrical energy in the generated field. It consists of two conductive plates separated by a thin insulating dielectric layer; in practice, it is a pair of thin strips of metal foil coiled together to increase surface area per unit volume, and hence capacitance. The unit of capacitance is the farad, named after Michael Faraday and denoted by the symbol F: one farad is the capacitance that creates a potential difference of one volt when storing a charge of one coulomb. A current first flows through a capacitor connected to a power source, since charge accumulates in the capacitor; this current will, however, decrease as the capacitor is charged, and eventually become zero. The capacitor therefore does not pass D.C., but blocks it.

An inductance is a conductor, usually a coil of wire, that stores energy in a magnetic field generated when a current is passed through it. When the current changes, the magnetic field also changes, creating a voltage between the ends of the conductor. The induced voltage is proportional to the rate of change of current. The coefficient of proportionality is called inductance. The unit of inductance is the henry, named after Joseph Henry, a contemporary of Faraday. A one henry inductance is an inductance that causes a potential difference of one volt at a rate of change of current through it of one ampere per second. The behavior of an inductor is the opposite of that of a capacitor: it will freely pass direct current and block rapidly changing current.

Electric power

Electrical power is the rate at which electrical energy is transferred by an electrical circuit. The SI unit of power is the watt, equal to one joule per second.

Electrical power, like mechanical power, is the rate at which work is done, measured in watts and denoted by the letter P. The term power consumption, used colloquially, means "electrical power in watts." The electrical power in watts produced by an electric current I equal to the passage of a charge Q coulomb every t seconds through an electrical potential difference (voltage) V is

P = QV/t = IV

  • Q - electric charge in coulombs
  • t - time in seconds
  • I - electric current in amperes
  • V - electric potential or voltage in volts

Electricity generation is often produced by electric generators, but can also be generated by chemical sources such as electric batteries or by other means using a wide variety of energy sources. Electrical power is typically supplied to businesses and homes by electric utilities. Electricity is usually billed per kilowatt-hour (3.6 MJ), which is the generated power in kilowatts multiplied by the running time in hours. In the electric power industry, power measurements are made using electricity meters, which remember the amount of total electrical energy given to the client. Unlike fossil fuels, electricity is a low-entropy form of energy and can be converted into motion energy or many other types of energy with high efficiency.

Electronics

Electronics deals with electrical circuits, which include active electrical components such as vacuum tubes, transistors, diodes, and integrated circuits, and their associated passive and switching elements. The non-linear behavior of active components and their ability to control the flow of electrons allows the amplification of weak signals and the widespread use of electronics in information processing, telecommunications and signal processing. The ability of electronic devices to act as switches allows for digital processing of information. Switching elements such as printed circuit boards, layout technology and other various forms communication infrastructure complement the functionality of the circuit and turn dissimilar components into a normal working system.

Today, most electronic devices use semiconductor components to implement electronic control. The study of semiconductor devices and related technologies is regarded as a branch of solid state physics, while the design and construction of electronic circuits for solving practical problems belongs to the field of electronics.

Electromagnetic waves

The work of Faraday and Ampère showed that a time-varying magnetic field generated an electric field, and a time-varying electric field was the source of the magnetic field. Thus, when one field changes over time, another field is always induced. Such a phenomenon has wave properties and is naturally called an electromagnetic wave. Electromagnetic waves were theoretically analyzed by James Maxwell in 1864. Maxwell developed a set of equations that could unambiguously describe the relationship between an electric field, a magnetic field, an electric charge, and an electric current. He was also able to prove that such a wave necessarily propagates at the speed of light, and thus light itself is a form. electromagnetic radiation. The development of Maxwell's laws, which combine light, fields and charge, is one of the milestones in the history of theoretical physics.

Thus, the work of many researchers has made it possible to use electronics to convert signals into high-frequency oscillatory currents, and through suitably shaped conductors, electricity allows these signals to be transmitted and received via radio waves over very long distances.

Production and use of electrical energy

Generation and transmission of electric current

In the 6th century BC e. Greek philosopher Thales of Miletus experimented with amber rods, and these experiments were the first studies in the field of electrical energy production. While this method, now known as the triboelectric effect, could only lift light objects and generate sparks, it was extremely inefficient. With the invention of the voltaic pole in the eighteenth century, a viable source of electricity became available. Voltaic pillar and his modern descendant- an electric battery that stores energy in a chemical form and gives it out in the form of electrical energy on demand. The battery is a versatile and very common power source that is ideal for many applications, but the energy stored in it is finite and once it is used up, the battery must be disposed of or recharged. For large needs, electrical energy must be generated and transmitted continuously through conductive power lines.

Electricity is typically generated by electromechanical generators driven by steam from burning fossil fuels or heat from nuclear reactions; or from other sources such as kinetic energy extracted from wind or running water. Modern steam turbine, developed by Sir Charles Parsons in 1884, today produces about 80 percent of the world's electricity using various heat sources. Such oscillators bear no resemblance to Faraday's 1831 unipolar disk oscillator, but they still rely on his electromagnetic principle, according to which a conductor, by interlocking with a changing magnetic field, induces a potential difference at its ends. The invention of the transformer at the end of the 19th century meant that electrical energy could be transferred more efficiently at higher voltage but lower current. Efficient electrical transmission means, in turn, that electricity can be generated in centralized power plants, benefiting from economies of scale, and then transmitted over relatively long distances to where it is needed.

Since electrical energy cannot easily be stored in quantities sufficient to meet the needs on a national scale, it must be produced at any time as much as in this moment it is required. This obliges utilities to carefully predict their electrical loads and constantly coordinate these data with power plants. Some amount of generating capacity should always be kept in reserve as a safety net for the electricity grid in case of a sharp increase in demand for electricity.

The demand for electricity is growing at a rapid pace as the country modernizes and develops its economy. The United States experienced a 12 percent growth in demand during the first three decades of the 20th century each year. This growth rate is currently being seen in emerging economies such as India or China. Historically, the growth rate of demand for electricity has outpaced the growth rate of demand for other types of energy.

Environmental concerns related to electricity generation have led to increased attention to electricity generation from renewable sources, in particular wind and hydroelectric power plants. Although one can expect continued debate about the impact on environment various means of generating electricity, its final form is relatively pure.

Ways to use electricity

The transmission of electricity is a very convenient way of transmitting energy, and it has been adapted to a huge and growing number of applications. The invention of the practical incandescent light bulb in the 1870s led to lighting being one of the first mass-available uses of electricity. Although electrification came with its own risks, the replacement of open-flame gas lighting greatly reduced the fire hazard inside homes and factories. Public utilities have been established in many cities to cater to the growing electric lighting market.

The heating resistive Joule effect is used in the filaments of incandescent lamps and also finds more direct application in systems electric heating. Although this method of heating is versatile and manageable, it can be considered wasteful, since most methods of electricity generation already require the production of thermal energy in a power plant. A number of countries, such as Denmark, have issued laws restricting or prohibiting the use of resistive electrical heating in new buildings. Electricity, however, is still a very practical source of energy for heating and cooling, with air conditioners or heat pumps representing a growing demand sector for heating and cooling electricity, the consequences of which utilities are increasingly required to consider.

Electricity is used in telecommunications, and in fact the electric telegraph, which was demonstrated commercially in 1837 by Cook and Wheatstone, was one of the earliest electrical telecommunications applications. With the construction of the first intercontinental, and then transatlantic, telegraph systems in the 1860s, electricity made it possible to communicate within minutes with the entire globe. Fiber optics and satellite communications have taken part of the communications market, but electricity can be expected to remain an important part of this process.

The most obvious use of the effects of electromagnetism occurs in the electric motor, which is a clean and efficient means of propulsion. A stationary motor, such as a winch, is easy to provide power, but a motor for a mobile application, such as an electric vehicle, either needs to move power supplies such as batteries with it or collect current with a sliding contact known as a pantograph.

Electronic devices use a transistor, perhaps one of the major inventions twentieth century, which is the fundamental building block of all modern schemes. A modern integrated circuit can contain several billion miniaturized transistors in an area of ​​just a few square centimeters.

Electricity is also used as a source of fuel for public transport, including in electric buses and trains.

The effect of electricity on living organisms

The effect of electric current on the human body

Voltage applied to the human body causes an electrical current to flow through tissues, and although this relationship is non-linear, the greater the voltage applied, the greater the current. The sensing threshold varies with power frequency and location of current flow, and is approximately 0.1 mA to 1 mA for mains frequency electricity, although currents as small as one microampere may be detected as an electrovibration effect under certain conditions. If the current is large enough, it can cause muscle contraction, cardiac arrhythmia, and tissue burns. The absence of any visible indication that a conductor is live makes electricity especially dangerous. The pain caused by the electric shock can be intense, leading to electricity being sometimes used as a method of torture. The death penalty carried out by electric shock is called execution in the electric chair (electrocution). Electrocution is still a form of judicial punishment in some countries, although its use has become rarer in Lately.

Electrical phenomena in nature

Electricity is not a human invention, it can be observed in several forms in nature, a notable manifestation of which is lightning. Many interactions familiar at the macroscopic level, such as touch, friction, or chemical bond, are due to interactions between electric fields at the atomic level. The Earth's magnetic field is believed to be due to the natural production of circulating currents in the planet's core. Some crystals, such as quartz, or even sugar, are capable of creating a potential difference across their surfaces when subjected to external pressure. This phenomenon, known as piezoelectricity, from the Greek piezein (πιέζειν), meaning "to press", was discovered in 1880 by Pierre and Jacques Curie. This effect is reversible, and when a piezoelectric material is subjected to an electric field, there is a slight change in its physical dimensions.

Some organisms, such as sharks, are able to detect and respond to changes in electrical fields, an ability known as electroreception. At the same time, other organisms, called electrogenic, are able to generate voltages themselves, which serves them as a defensive or predatory weapon. Fish of the hymniformes order, of which the electric eel is the most famous member, can detect or stun their prey using high voltage generated by mutated muscle cells called electrocytes. All animals transmit information across cell membranes with voltage impulses called action potentials, whose function is to provide the nervous system with a connection between neurons and muscles. Electric shock stimulates this system and causes muscle contraction. Action potentials are also responsible for coordinating the activities of certain plants.

In 1850, William Gladstone asked scientist Michael Faraday what the value of electricity was. Faraday replied, "One day, sir, you will be able to tax him."

During the 19th and early 20th centuries, electricity was not part of the daily lives of many people, even in the industrialized western world. Popular culture of the time accordingly often portrayed him as a mysterious, quasi-magical force that could kill the living, raise the dead, or otherwise change the laws of nature. This view began to reign with the experiments of Galvani in 1771, in which the legs of dead frogs were shown to twitch when animal electricity was applied. The "revival" or resuscitation of apparently dead or drowned persons has been reported in medical literature shortly after Galvani's work. These reports became known to Mary Shelley when she set about writing Frankenstein (1819), although she does not indicate such a method of bringing the monster to life. Reviving monsters with electricity became a hot topic in horror films later.

As public acquaintance with electricity as a source of life force the second industrial revolution, its owners were more often shown in a positive light, such as electricians, about whom it is said "death through gloves chills their fingers weaving wires" in Rudyard Kipling's 1907 poem "The Sons of Martha". A variety of electrically powered vehicles figured prominently in the adventure stories of Jules Verne and Tom Swift. Electricity professionals, whether fictional or real - including scientists such as Thomas Edison, Charles Steinmetz or Nikola Tesla - were widely perceived as magicians with magical powers.

As electricity ceased to be a novelty and became a necessity in everyday life in the second half of the 20th century, it received special attention from popular culture only when it ceased to flow, which was an event that usually signals a disaster. . People who supported his entry, such as the unnamed hero of Jimmy Webb's Wichita Fixer (1968), were increasingly presented as heroic and magical characters.

Electricity is a stream of particles moving in a certain direction. They have some charge. In another way, electricity is the energy that is obtained when moving, as well as the lighting that appears after receiving energy. The term was coined by William Gilbert in 1600. When conducting experiments with amber, the ancient Greek Thales discovered that a charge was acquired by the mineral. "Amber" in Greek means "electron". That's where the name came from.

Electricity is...

Thanks to electricity, an electric field is created around current conductors or bodies with a charge. Through it, it becomes possible to influence other bodies, which also have a certain charge.

Everyone knows that charges are positive and negative. Of course, this is a conditional division, but according to the current history, they continue to be designated as such.

If the bodies are charged the same way, they will repel, and if they are different, they will attract.

The essence of electricity is not only the creation of an electric field. There is also a magnetic field. Therefore, there is a relationship between them.

More than a century later, in 1729, Stephen Gray established that there are bodies that have very high resistance. They are able to conduct

At present, thermodynamics is most concerned with electricity. But the quantum properties of electromagnetism are studied by quantum thermodynamics.

Story

It is hardly possible to name a specific person who discovered the phenomenon. After all, to this day, research continues, new properties are revealed. But in the science that we are taught at school, several names are called.

It is believed that the first who became interested in electricity was living in ancient Greece. It was he who rubbed the amber on the wool and watched how the bodies began to be attracted.

Aristotle then studied eels, which struck enemies, as they later understood, with electricity.

Pliny later wrote about the electrical properties of resin.

A number of interesting discoveries were assigned to the physician of the English Queen, William Gilbert.

In the middle of the seventeenth century, after the term "electricity" became known, the burgomaster Otto von Guericke invented the electrostatic machine.

In the eighteenth century, Franklin created a whole theory of the phenomenon, saying that electricity is a fluid or immaterial liquid.

In addition to the people mentioned, such famous names are associated with this issue, such as:

  • Pendant;
  • Galvani;
  • Volt;
  • Faraday;
  • Maxwell;
  • Ampere;
  • Lodygin;
  • Edison;
  • Hertz;
  • Thomson;
  • Claude.

Despite their undeniable contribution, Nikola Tesla is rightfully recognized as the most powerful of the scientists in the world.

Nikola Tesla

The scientist was born into the family of a Serbian Orthodox priest in what is now Croatia. At the age of six, the boy discovered a miraculous phenomenon when playing with a black cat: her back suddenly lit up with a strip blue color, which was accompanied by sparks when touched. So the boy first learned what "electricity" is. This determined his whole future life.

The scientist owns inventions and scientific work O:

  • alternating current;
  • air;
  • resonance;
  • field theory;
  • radio and much more.

Many associate the event, which was named with the name of Nikola Tesla, believing that the huge explosion in Siberia was not caused by the fall of a cosmic body, but by an experiment conducted by a scientist.

natural electricity

At one time in scientific circles there was an opinion that electricity does not exist in nature. But this version was refuted when Franklin established the electrical nature of lightning.

It was thanks to her that amino acids began to be synthesized, which means that life appeared. It has been established that movements, breathing and other processes occurring in the body arise from a nerve impulse, which is of an electrical nature.

Well-known fish - electric rays - and some other species are protected in this way, on the one hand, and hit the victim, on the other.

Application

Electricity is connected through the operation of generators. Power plants create energy that is transmitted through special lines. Current is generated by converting internal or electrical. Stations that produce it, where electricity is connected or disconnected, are various kinds. Among them are:

  • wind;
  • solar;
  • tidal;
  • hydroelectric power plants;
  • thermal atomic and others.

Connecting electricity today occurs almost everywhere. Imagine life without him modern man can not. With the help of electricity, lighting is produced, information is transmitted by telephone, radio, television ... Due to it, transport such as trams, trolleybuses, electric trains, metro trains functions. Electric vehicles are appearing and making themselves known more and more boldly.

If there is a power outage in the house, then a person often becomes helpless in various matters, since even household appliances work with the help of this energy.

Unsolved mysteries of Tesla

The properties of the phenomenon have been studied since ancient times. Mankind has learned how to conduct electricity using various sources. It made their life much easier. Nevertheless, in the future, people still have many discoveries related to electricity.

Some of them may even have already been made famous by Nikola Tesla, but then were classified or destroyed by himself. Biographers claim that at the end of his life, the scientist himself burned most of the records, realizing that humanity was not ready for them and could harm itself by using his discoveries as the most powerful weapon.

But according to another version, it is believed that some of the records were seized by US intelligence agencies. History knows the US Navy destroyer Eldridge, which not only had the ability to be invisible to radar, but also moved instantly in space. There is evidence of an experiment, after which part of the crew then died, another part disappeared, and the survivors went crazy.

One way or another, it is clear that all the secrets of electricity have not yet been revealed. This means that humanity is not yet morally ready for this.

ELECTRICITY

ELECTRICITY, a form of energy that exists in the form of static or moving ELECTRIC CHARGES. Charges can be positive or negative. Like charges repel, opposite charges attract. The forces of interaction between charges are described by the Coulomb's LAW. When charges move in a magnetic field, they experience a magnetic force and in turn create an oppositely directed magnetic field (FARADAY'S LAWS). Electricity and MAGNETISM are different aspects of the same phenomenon, ELECTROMAGNETISM. The flow of charges forms an ELECTRIC current, which in the conductor is a flow of negatively charged ELECTRONS. In order for an electric current to arise in the CONDUCTOR, an ELECTRIC DRIVE FORCE or POTENTIAL DIFFERENCE between the ends of the conductor is necessary. Current that moves in only one direction is called direct current. This current is created when the source of the potential difference is the BATTERY. A current that changes direction twice in a cycle is called variable current. The source of such current is the central network. The unit of current is the ampere, the unit of charge is the pendant, the ohm is the unit of resistance, and the volt is the unit of electromotive force. The main means for calculating the parameters of an electrical circuit are Ohm's LAW and KIRCHHOFF'S LAWS (on the summation of voltage and current in a circuit). see also ELECTRICITY, ELECTRONICS.

Electrical energy can be obtained by induction in a generator; the voltage in the primary winding creates an alternating current in the external circuit. The presence of inductance or capacitance (or both) results in a phase shift (A) between voltage V and current I. The figure shows that the capacitance caused a phase shift of 90°, resulting in an average power value of 0, although the power curve no still looks like a sine wave. The power reduction P caused by the phase shift is called the power factor. If three phases of alternating current are displaced between themselves, each by 120°, then the sum of their current or voltage values ​​will always be equal to zero (V). Such three-phase currents are used in short-circuited induction motors with a rotor (C). In this design, there are three electromagnets rotating in the generated magnetic field. Alternating current is also produced in closed (D) and open (E) oscillatory circuits. The high frequency electromagnetic waves used in some communication systems ARE PRODUCED BY TEKIM1 circuits.


Scientific and technical encyclopedic dictionary.

Synonyms:

See what "ELECTRICITY" is in other dictionaries:

    - (from the Greek elektron amber, as amber attracts light bodies). A special property of some bodies, which manifests itself only under certain conditions, for example. friction, heat, or chemical reactions, and revealed by the attraction of lighter ones ... ... Dictionary of foreign words of the Russian language

    ELECTRICITY, electricity, pl. no, cf. (Greek elektron). 1. Substance underlying the structure of matter (physical). || Peculiar phenomena accompanying the movement and movement of particles of this substance, the form of energy (electric current, etc.) ... Explanatory Dictionary of Ushakov

    A set of phenomena caused by the existence, movement and interaction of charged bodies or particles of electric charge carriers. The connection of electricity and magnetism, the interaction of motionless electric charges is carried out ... ...

    - (from the Greek elektron amber) a set of phenomena in which the existence, movement and interaction (by means of an electromagnetic field) of charged particles are detected. The doctrine of electricity is one of the main branches of physics. Often under... Big Encyclopedic Dictionary

    Lepisdrichestvo, electric current, lepistrichestvo, lepistrichestvo, current, electricity, lighting Dictionary of Russian synonyms. electricity n., number of synonyms: 13 actinoelectricity ... Synonym dictionary

    ELECTRICITY- in the most general sense represents one of the forms of motion of matter. Usually, this word means either an electric charge as such or the very doctrine of electric charges, their movement and interaction. The word E. comes from the Greek. electron... Big Medical Encyclopedia

    electricity- (1) EN electricity (1) set of phenomena associated with electric charges and electric currents NOTE 1 - Examples of usage of this concept: static electricity, biological effects of electricity. NOTE 2 - In… … Technical Translator's Handbook

    ELECTRICITY, a, cf. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

    Electricity- - 1. The manifestation of one of the forms of energy inherent in electric charges, both moving and in a static state. 2. The field of science and technology associated with electrical phenomena. [ST IEC 50(151) 78] Term rubric:… … Encyclopedia of terms, definitions and explanations of building materials

    ELECTRICITY- a set of phenomena in which the existence, movement and interaction (by means of an electromagnetic field) of electric charges are found (see (4)). The doctrine of electricity is one of the main branches of physics ... Great Polytechnic Encyclopedia