Itseinduktanssi

Itseinduktanssi is a fundamental property of an electrical conductor or circuit that quantifies its opposition to changes in the electric current flowing through it. This opposition arises from the magnetic field produced by the current itself. When the current in a conductor changes, the magnetic flux through the circuit also changes. According to Faraday's law of induction, this changing magnetic flux induces an electromotive force (EMF), commonly known as a back EMF, in the conductor. This induced EMF is always in a direction that opposes the change in current that caused it, a principle described by Lenz's Law.

The magnitude of the self-induced EMF is directly proportional to the rate of change of the current. The constant of proportionality is the inductance, denoted by the symbol L. Inductance is measured in henries (H). A higher inductance means a greater ability of the circuit to oppose changes in current. Factors influencing inductance include the geometry of the conductor, such as its shape, size, and the number of turns in a coil, as well as the magnetic properties of the material in which the magnetic field is established. For example, a coil with a ferromagnetic core will have a much higher inductance than an air-cored coil of the same dimensions.

Self-inductance plays a crucial role in the behavior of electrical circuits, particularly those containing coils or inductors. It is responsible for phenomena like sparking when switches are opened in circuits with significant inductance, and it is a key component in many electronic circuits, including filters, oscillators, and transformers. The energy stored in the magnetic field of an inductor is given by the formula E = 1/2 * L * I^2, where L is the inductance and I is the current.