Electric current in metals – causes and examples of application

The origin of many processes in the universe has not yet been fully understood. For example, scientists cannot yet explain exactly who “allowed” electrons under the influence of an alternating magnetic field to move in metal conductors. Despite this, such an important phenomenon as electric current in metals has been successfully “tamed” by man and has been used over the past two centuries.

Where does the current come from

It should be noted that electric current can be generated not only in a metal conductor, but also in other substances. For example, atmospheric energy appears in rain clouds, but it is not possible to use it. Coils of copper generator sets are ideal for generating electricity for household needs.

Electric current in metals is created by the ordered movement of electrons. The term “Electricity” was first coined by William Gilbert in the 16th century, but the naturalist limited himself to receiving electrical discharges of static electricity. Two centuries later, Michael Faraday has already created a working model of a dynamo machine, the birth of which is due precisely to the effect of the formation of electricity in metals.

The scientist improved the previously known physical experiment, in which a current in metals was created by the movement of a magnetic field around a static metal object. The first generator consisted of a rotating permanent magnet and a copper coil. Such a machine made it possible to obtain a relatively low voltage in the conductor. At that time, it was not yet known for certain what particles create a current in metals. Only in 1913, scientists were able to prove the electronic nature of this phenomenon.

Experiments to determine the causes of stress in metals were initiated by the Russian scientists L.I. Mandel’shtam and N.D. Papaleksi. Three years later, physicists R. Tolman and B. Stewart significantly improved the technique, which made it possible to carry out quantitative measurements.

To obtain accurate results, scientists had to create special machines, thanks to the use of which it was possible to determine the cause of the current. If we briefly summarize the essence of the experiments carried out in order to prove the electronic nature of the appearance of the current, then we get a summary of the following content:

  • It is necessary to prepare a coil that can rotate around its axis.
  • Place the product on a hard surface such as the floor.
  • Connect the output of the conductors of this electrical machine to a galvanometer.
  • Spin the coil (rotation speed should be high).
  • Slowly brake the device.

As a result of the experiment, an electrical impulse arises, which can be registered with a measuring device. Only the presence of charged particles, which are called electrons, could cause the appearance of voltage in the circuit. These elements are influenced, like any solid body, by the force of inertia, which makes them “exit” from the conductor after an abrupt stop of the coil.

Calculation formula

The exact calculation of the specific charge (em) in metals can be determined using the following formula:

Em = lu0Rq


l is the current that instantly appears in the conductor when the coil stops;
u 0 – the initial linear speed of the turns of the wire;
R is the resistance of the circuit;
q – charge.

Experiments carried out by R. Tolman and B. Stewart made it possible to streamline previously obtained information from other scientists. Despite this, electrical conductors have been actively used in electrical products since the beginning of the 19th century, proof of the electronic nature of current in metals, has made it possible to accelerate the emergence of complex devices.

Application of this phenomenon

The reports of the experiments carried out quickly became widespread not only in scientific circles. Of course, it was impossible to call such a phenomenon a discovery of the century, but when calculating the circuits of devices of a high class of accuracy, it was already impossible to do without taking into account the behavior of electrons.

Thanks to the movement of electrons in metals, it is possible to charge batteries. The construction of power lines is also carried out taking into account the movement of electrons in metals. In general, almost all electrical devices operate on conductors in which the presence of this phenomenon is mandatory.

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