PREFACE TO THE PRESENT EDITION The present book titled, Electromagnetics: General theory of the electromagnetic field. Classical and relativistic approaches, is an extended form of the previous two editions of the books titled Electromagnetics: General theory of the electromagnetic field. The new book, at the difference of the previous ones, contains four new appendices, devoted to several topics, as follows: a. A study on the divergence of tensors related to the curvature of the space-time continuum; b. The energy-momentum tensor of the electromagnetic field in the theory of relativity; c. The Sagnac effect in The General theory of relativity; d. A new approach to the calculation of the magnetic field strength of a solenoid and to the introduction of magnetic quantities. In this book, apart from some improvements, new results have been included, some of them belonging to the author. These last ones have been presented at the ICAEM International Conference of Applied and Engineering Mathematics, held in London the last four years (2008-2011). The book will appear in both forms electronic and print. The volume has been built in order to avoid the reader to resort to books of mathematics, all mathematical developments being included in the book. The purpose of this book has been to present in a legible manner some important subjects of the concerned topics. At the same time, the text has been so prepared that a reader not interested in the Special Theory of Relativity and General Theory of Relativity could read it, avoiding the text connected with the relativistic treatment. The book is devoted to all readers interested in these topics.
PREFACE TO THE FIRST EDITION In the present work the physical fundamentals of electromagnetic phenomena are studied having in view their technical applications. The book contains the general theory of the electromagnetic field necessary for the study of the principal applications in the following domains: Electrostatics, Electrokinetics, Electrodynamics and Magnetostatics. The general theory contains the introduction (i.e., the definition) of fundamental concepts among which: field and substance, electric charge, electric current, state quantities of electric and magnetic fields, as well as the study of laws and energy of the electromagnetic field. The general theory is presented in four chapters. Further, three appendices are added. For practical applications, the consideration of electromagnetic phenomena at a macroscopic scale is of special interest. However, in many applications, it is necessary to know the phenomena at a microscopic scale. At the same time, it is useful to have in view that the physical model is, in many cases, relatively simple in the case of a microscopic study. For this reason, in this work, the
