Electromagnetic induction surrounds us everywhere.Even at this moment, when you read these lines from the screen of your electronic device, the cells of the body are affected. However, you should not worry about it, because its intensity is so insignificant that it is only of theoretical interest. However, in certain conditions, electromagnetic induction can increase to dangerous values. As you know, human security depends primarily on him. Therefore, it is necessary to have at least a general idea of what electromagnetic induction is.
Let's put a simple thought experiment.To do this, we will need a metal hoop ring, in the gap of which a sensitive ammeter and a low-power incandescent lamp are consistently included. This hoop will be a closed loop through which alternating electric current can flow. The ring itself is insulated: for example, covered in a plastic shirt. The second necessary element is the long wire through which current flows. The voltage here should be higher. We place the hoop in one room, and the wire - in another. Obviously, the ammeter in the metal ring will show zero - really, where does the current come from there ?! Now we place the wire directly on the ring ... At this moment, if the voltage value is not too small, the instrument needle deviates from zero. Miracles! After all, the electrons from the wire cannot jump to the metal of the ring, since the last thing we have specifically indicated is insulated with a non-conductive plastic. Let's complicate our experiment: we wind the wire on the hoop. Now the arrow of the ammeter clearly indicates the presence of electric current in the ring. The reason for this is electromagnetic induction. To explain what is happening from a scientific point of view, you will have to take a short excursion into history.
The discovery of electromagnetic induction in 1831attributed to M. Faraday. Ten years before that, he set out to transform magnetic fields into electrical energy and, apparently, brilliantly coped with this. Already at that time physicists knew that there are two types of fields - magnetic and electric. If charge carriers move, then the field of magnetic nature is recorded, and if stationary, then electrostatic. Many then assumed that the fields should be somehow interconnected, but confirming this practical experience and its justification was made by Faraday. He moved the smaller coil inside the larger one. The conclusions of one of them were connected to the measuring device, and the coils of the other flowed direct current. The occurrence of the movement of particles in the circuit is called induced (induced) current. If the charged particles move directionally, then a magnetic field appears around them. In order for induction to occur, the intensity lines of this field must cross the conducting circuit. Both the contour itself and the field can shift - the result is the same. Replacing the direct current (Faraday's experience) with an alternating current allows you to avoid any mechanical movements, since the generated field itself changes in time. The use of electromagnetic induction allowed the creation of 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 transmission lines transmit voltages in the thousands of volts. Because of this, the existing field around the wires can extend 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.
