Induktancja

Induktancja, often denoted by the symbol L, is a fundamental electrical property of a circuit element, typically a coil of wire, that describes its ability to store energy in a magnetic field when an electric current flows through it. It is a measure of how much a change in current will induce a voltage in that same circuit element. The SI unit of inductance is the Henry (H), named after the American physicist Joseph Henry.

When the current in an inductor changes, it creates a changing magnetic flux. According to Faraday's law of induction, this changing magnetic flux induces an electromotive force (EMF), or voltage, in the inductor itself. This induced voltage opposes the change in current that caused it, a phenomenon known as self-inductance. The magnitude of this induced voltage is directly proportional to the rate of change of the current and the inductance value. Mathematically, this relationship is expressed as V = -L(dI/dt), where V is the induced voltage, L is the inductance, and dI/dt is the rate of change of current with respect to time.

Inductors are passive components used in a wide variety of electronic circuits. They are essential for filtering, tuning, and energy storage applications. In AC circuits, inductors exhibit inductive reactance, which is the opposition to the flow of alternating current due to the inductance. This reactance increases with frequency. Inductance depends on the physical characteristics of the inductor, such as the number of turns in the coil, the geometry of the coil (its length and diameter), and the magnetic permeability of the core material surrounding the coil. Air-cored inductors have lower inductance values compared to inductors with ferromagnetic cores.