Faraday's experiments have made an invaluable contribution to the formation of modern science. A simple boy from a poor family has made a real breakthrough in physics. Among his experimental discoveries is the law of electromagnetic induction, the phenomenon of electrolysis, Faraday's cylinder. The scientist not only sought to put new experiments - he built a completely understandable theory of electromagnetic phenomena, based on experimental data.
Michael Faraday was the son of a blacksmith. Elementary knowledge he received at the school for the poor, where he learned to read, write and count. At the age of nine, Faraday carries newspapers, and later his father defines him as a bookbinder student. The inquisitive boy read all the books that he was given to the weave. But most of all he liked scientific treatises. So the future scientist expanded his horizons and got acquainted with the latest achievements of modern science. A wonderful event brought him down with Sir Davy, who took him to the secretaries.
The new profession gave him the opportunity to travel around the world and maintain an acquaintance with the great scientists of that time - Volta, Gay-Lussac, Amper. It was under the influence of great people that Faraday began his scientific activity.
In October 1832, the first entry in Faraday's diaries was: "When the current passes, the area of the painted areas on paper changes." This observation served as the first impetus to the interaction of chemical reactions and electrical phenomena. The deflection of the magnetic needle under the action of an electric current served as a young scientist's basis for his own discovery. Michael Faraday began to study the nature of electrical phenomena.
The discovery of Faraday
Experiments on the study of induction effects began about 200 years ago by Joseph Henry and Michael Faraday. Scientists examined the electric current using two wire spirals that were wound on a spool made of wood. One of these spirals joined the galvanometer, which registered weak currents. The second spiral was connected with a galvanic battery. At the moment of closing and opening of the circuit, the indicator needle of the galvanometer must be deflected.
Thus Faraday's experiments 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 appearance of an electric current in a closed loop with a changing magnetic flow with time, which this circuit permeates. Faraday's further experiments were devoted to the study of this phenomenon.
Investigation of EMR
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 as follows: when a magnet is placed in a coil, an electric current arises in the circuit, while a current is also produced in the circuit, but of a different direction. The appearing voltage depends on the speed of the magnet and on which pole it is immersed in the coil.
The second experiment concerned the occurrence of a current in one coil when the voltage was changed in another. As Faraday has shown, such a phenomenon arises at the moment of supply (termination) of the current in the first element.
Having carried out numerous experiments, Faraday proved that in closed circuits the voltage arises only in the case when the given circuit falls into an alternating magnetic field. The current arising in this case is called self-inductive or inductive.
Modern science claims that in the electrical circuit there is not a definite current, but an electromotive force (EMF) that provokes its appearance. Experiments have shown that an EMF occurs in the circuit when the magnetic flux changes. Its formula can be written as follows:
The meaning of this expression is that the EMF is equal to the rate of change of the magnetic flux, mapped with a minus sign. Faraday's formula bears his name and reflects this law: the emf of induction is equal to the rate of change of the magnetic flux through the contour. The minus sign in this expression is due to the appearance of the Lenz rule.
The first generator
In 1831, a scientist built a Faraday generator to demonstrate the process of converting mechanical energy into electrical energy. This device had no practical significance, but it clearly showed the magic of the appearance of an electric current.
The 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 was left stationary. Surprising observers caused the fact that the rotation of the magnet together with the disk led to the appearance of an electromotive force in the stationary chain. This phenomenon was 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.
Faraday's experiments were not limited to the study of magnetic fields. Most of the modern ideas about electrolysis and ions are due to the appearance of this English scientist. Faraday reduced a vast series of experiments on the study of the behavior of chemical solutions in an electric field to two simple laws, which we are using at the present time:
- The mass of matter formed during electrolysis on electrodes is directly proportional to the product of time per current (i.e., 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.
During the experiments, Faraday proved that to obtain 1.008 kg of hydrogen, it is necessary to spend 96.5 million cuons 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 necessary to obtain one chemical equivalent of the substance was called the Faraday number.
The enormous contribution that this extraordinary and talented scientist made to physics puts him on the same level as Newton, Joel, Einstein and other great people.