ABSTRACT
Electromagnetism was the first theory to unite sciences of electricity and magnetism. The rate of flow of charge is the electric current. In most materials, the electron orbit is completely random, and so there is no perceptible magnetic field. Electromagnetic field theory is really the result of the union of several distinct sciences. The oldest of these is electrostatics, which was first studied by the Greeks. It was in 1785 that French physicist, Charles Augustin de Coulomb, showed that electrically charged materials sometimes attract and sometimes repel each other. Among other things, Maxwell was able to predict the existence of electromagnetic waves. In some materials, the electrons are very tightly bound to nucleus and considerable energy must be expended to remove an electron. We should note that the mass of a proton is 1837 times the mass of an electron; conduction in metals is by electron flow. The chapter also presents an overview of the key concepts in this book.
