Electric and Magnetic Fields: Concepts and Sources

At the heart of electrical engineering lies the fundamental concept of fields. Fields are physical quantities that have a value at every point in space. They provide a way to describe the influence of objects, like electric charges or currents, on other objects without direct contact. Understanding these invisible forces is crucial for designing everything from simple circuits to complex wireless systems.

We begin with the electric field, often denoted by the symbol "E". This field is defined as the force per unit positive charge that would be exerted on a test charge placed at a given point. Think of it as a map showing the direction and strength of the electric force everywhere in space, independent of whether a test charge is actually there.