Electromagnetism

A good knowledge of electromagnetism, the part of physics that deals with the relationships between electrical and magnetic phenomena, is one of the basic requirements of an electrical engineer. We have therefore endeavored to present a logical, precise and useful presentation that can even enhance the general culture of the electrical engineer.

Before going into detail on each point, we would like to point out that we have adopted the notation and system of units defined by French and international standards [Bureau International des Poids et Mesures (1985), Union Technique de l'Électricité (1981), Union Internationale de Physique Pure et Appliquée (1965)] (cf. articles Unités légales et facteurs de conversion [A 24] in the Plastiques et Composites treatise and Giorgi's MKSA system of units [D 50] in the Génie électrique treatise). We therefore use the following vocabulary:

• for basic quantities :

• for sources :

• in the case of linear relationships :

This is particularly important in the field of electromagnetism, where it's hard to claim unanimity! All the considerations that lead us to show that one system is better than all the others seem to us to be artificial: a system is good if it allows different types of quantities to be identified by different types of symbols, while remaining as close as possible to physical reality.

• Considerations of pure logic show that a relationship whose field of validity is unknown is useless and can even be dangerous. We have therefore sought to show the origin of the different relationships by distinguishing, from the outset of the article, between the general laws of electromagnetism (Maxwell's equations and the energy relationship) and the particular relationships corresponding to different materials. This is how we distinguish between a general law