ABSTRACT
One might argue that “electricity” is the world’s most useless form of energy, i.e., useless until it is converted into some other form. It is because electrical energy is so controllable, and that it is readily converted into heat, light, sound, and mechanical force and motion, which makes it important to modern technology and engineering. This book is concerned with engineering issues related to the conversion of energy from the mechanical into the electrical form, and vice versa. The “vice versa” comment in the previous statement implies that the conversion process is reversible, i.e., that energy can also be readily converted from the electrical into the mechanical form, which indeed can be, and in fact the same device can be typically used to convert energy either way. Such conversion processes inevitably involve electric charge in motion, or current, which in turn mandates the presence of magnetic fields.
