What is electromagnetic induction?

Electromagnetic induction surrounds us everywhere. Even at this point, when you read these lines from the screen of your electronic device, the cells of the body are affected. However, it is not worth worrying about, because its intensity is so insignificant that it is only of theoretical interest. However, under certain conditions, electromagnetic induction can increase to dangerous values. As is known, human security depends, first of all, on himself. Therefore, it is necessary to have at least a general idea of what is electromagnetic induction.

Let's put a simple thought experiment. To do this, we need a metal hoop ring, in which a sensitive ammeter and a low-power incandescent lamp are connected in series. This hoop will be a closed loop, through which an alternating current can flow . The ring itself is isolated: for example, it is hidden in a plastic shirt. The second necessary element is a long wire, through which current flows. The tension here should be higher. We place the hoop in one room, and the wire in the other. It is obvious that the ammeter in the metal ring will show zero - indeed, where does the current come from ?! Now we put the wire directly on the ring ... At this moment, if the voltage value is not too small, the arrow of the device deviates from zero. Miracles! After all, the electrons from the wire can not jump on the metal of the ring, since the last, as we specifically pointed out, is isolated by a non-conductive plastic current. Let's complicate our experiment: wrap the wire on the hoop. Now the ammeter needle clearly indicates the presence of an electric current in the ring . The reason for this is electromagnetic induction. To explain what is happening from a scientific point of view, it is necessary to make a short excursion into history.

The discovery of electromagnetic induction in 1831 is attributed to M. Faraday. Ten years before, he had set himself the goal of converting magnetic fields into electrical energy and, apparently, brilliantly coped with it. Already at that time physicists knew that there are two kinds of fields - magnetic and electrical. If charge carriers move, then a magnetic field is recorded, and if stationary, then electrostatic. Many then assumed that the fields should be somehow interconnected, but Faraday did justify this practical experience and substantiate it. He moved the smaller coil inside the larger one. The conclusions of one of them were connected to a measuring device, and the other was running at a constant current. The occurrence of particle motion in the circuit is called induced (induced) current. If the particles possessing a charge move in a directed manner, a magnetic field appears around them . In order to induce the induction, the lines of tension of this field must cross the conducting contour. The contour itself and the field can be shifted - the result is the same. The replacement of a direct current (the Faraday experience) by an alternating one allows to avoid any mechanical displacements, since the generated field itself varies in time. The use of electromagnetic induction has made it possible to create electrical energy transformers. Perhaps, electrical engineering would never have reached modern heights if there were no such devices.

What is the danger to man? Some lines of the transmission line transmit a voltage of thousands of volts. Because of this, the existing field around the wires can spread over several meters. In a person caught in such an alternating field, the water molecules are oriented along the lines of tension. Prolonged exposure to such conditions adversely affects many body systems.