Faraday experiments. Electromagnetic induction. Michael Faraday

The experiments of Faraday made an invaluable contribution to the formation of modern science. A simple poor boy made a real breakthrough in physics. Among his experimental discoveries is the law phenomenon of electrolysis, the faraday cylinder. The scientist not only sought to put new experiences - he built a completely understandable theory of electromagnetic phenomena, based on experimental data.

Start

Michael Faraday was the son of a blacksmith. Elementary knowledge he received in the school for the poor, where he learned to read, write and count. At the age of nine, Faraday spreads newspapers, and later his father identifies him as a bookbinder. An inquisitive boy read all the books that were given to him for weaving. But most of all he liked scientific treatises. So the future scientist expanded his horizons and became acquainted with the latest achievements of modern science. A wonderful case brought him to Sir Davy, who took him to the secretaries.

Faraday experiments

A new profession gave him the opportunity to travel the world and maintain familiarity with the great scientists of the time - Volta, Gay-Lussac, Ampere. It was under the influence of great people that Faraday began his scientific activity.

First discoveries

In October 1832, the first entry appeared in the diaries of Faraday: "With the passage of current, the area of ​​the colored areas on paper changes." This observation was the first impetus to the interaction of chemical reactions and electrical phenomena. The deviation of the magnetic needle under the action of electric current formed the basis of a young scientist for his own discovery. Michael Faraday began to study the nature of electrical phenomena.

Faraday Discovery

Experiments on the study of induction effects began about 200 years ago by Joseph Henry and Michael Faraday. Scientists investigated the electric current with the help of two wire spirals that were wound on a coil of wood. One of these spirals was attached to a galvanometer, which recorded weak currents. The second coil was connected with a galvanic battery. At the moment of closing and opening the circuit, the indicator arrow of the galvanometer is obligatorydeviated.

michael faraday

So the experiments of Faraday proved the existence of a relationship between magnetic and electric fields. The resulting relationship is called the "law of electromagnetic induction." Briefly, the meaning of this phenomenon can be described as the occurrence of an electric current in a closed circuit with a magnetic flux changing with time, which this circuit penetrates. Further Faraday experiments were devoted to the study of this phenomenon.

EMR research

One of the experiments showed that the interaction of a magnet and a coil with a current provokes the appearance of an induction current. Faraday explained this phenomenon in the following way: when a magnet is inserted into the coil, an electric current arises in the circuit, and the current, but in a different direction, also arises during removal. The voltage that appears depends on the speed of the magnet and on which pole it sinks into the coil.

electromagnetic induction law

The second experiment concerned the occurrence of current in one coil when the voltage changes to another. As Faraday proved, this phenomenon occurs at the time of the supply (cessation) of the current in the first element.

Having conducted numerous experiments, Faraday proved that in closed circuits the voltage arises only in the case when this circuit enters an alternating magnetic field. The resulting current is called self-guided or inductive.

Electromotive force

Modern science claims that not a certain current arises in an electrical circuit, but an electromotive force (EMF), which provokes its appearance. Experiments have shown that EMF occurs in the circuit when the magnetic flux changes. Its formula can be written as follows:

Faraday formula

The meaning of this expression is that the emf is equal to the rate of change of the magnetic flux, displayed with a minus sign. Faraday's formula bears his name and reflects such a law: the emf of induction is equal to the rate of change of the magnetic flux through the circuit. The minus sign in this expression owes its appearance to the Lenz rule.

First generator

In 1831, a scientist, in order to demonstrate the process of converting mechanical energy into electrical energy, built a Faraday generator. This device had no practical value, but clearly showed the magic of the occurrence of electric current.

Faraday disc was a device resembling a primitive generator. In this design, the magnetic field was directed along the axis of rotation, and the contour remained stationary. The surprise of the observers causedthat the rotation of the magnet together with the disk led to the appearance of an electromotive force in a fixed chain. This phenomenon has been called the Faraday Paradox. This contradiction was resolved after the death of the scientist, when an electron was discovered that behaves both as a charge and as a particle.

Electrolysis Studies

Faraday experiments were not limited to the study of magnetic fields. Most of the modern concepts of electrolysis and ions owe their appearance to this English scientist. An extensive series of experiments on the study of the behavior of chemical solutions in the electric field Faraday reduced to two simple laws, which we still use today:

  • The mass of a substance formed during electrolysis at the electrodes is directly proportional to the product of time and current (that is, the amount of electricity);
  • with the same amount of electricity, the mass of the substance formed on the electrodes is proportional to the chemical equivalent of the substance.faraday generator

During the experiments, Faraday proved that to obtain 1,008 kg of hydrogen it is necessary to spend 9.65 million pendant of electricity. The same amount of electricity is needed to produce 35.4 kg of chlorine, 63.6 / 2 kg of copper, 16/2 kg of oxygen.Thus, the measure of electricity required to produce one chemical equivalent of a substance was called the Faraday number.

The enormous contribution that this extraordinary and talented scientist made to physics puts him on the same level with Newton, Joule, Einstein and other great people.

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