Conclusion

The study of electrodynamics does not end with an introduction to electromagnetic induction and the magnetic properties of the substance. So far we have only considered the electromagnetic phenomena in the case of stationary electric charges (static electric field) and in the case of charges moving at a constant speed (static magnetic field). Only in the chapter "Electromagnetic induction" we have begun to study the time-variable electromagnetic field. A very wide, most interesting and practically most important area of variables and fast variable electromagnetic phenomena has been left out of this book.

Later, in the fourth book, based on knowledge of the laws of electrodynamics, which have already been studied, you will first get to know the properties, obtaining and application of alternating electric current. Then we will learn about another fundamental property of electromagnetic field: the generation of magnetic field by alternating electric field (the phenomenon of inverse electromagnetic induction). After that we will study the fast variable electromagnetic fields and electromagnetic waves. Only then will the acquaintance with electrodynamics be considered complete.