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Electromagnetic or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831, and James Clerk Maxwell mathematically described it as Faraday's law of induction .
Within two months, Faraday had found several other manifestations of electromagnetic induction. For example, he saw transient currents when he quickly slid a bar magnet in and out of a coil of wires, and he generated a steady current by rotating a copper disk near the bar magnet with a sliding electrical lead ("Faraday's disk").
The history of electromagnetic induction, a facet of electromagnetism, began with observations of the ancients: electric charge or static electricity (rubbing silk on amber), electric current , and magnetic attraction . Understanding the unity of these forces of nature, and the scientific theory of electromagnetism was initiated and achieved ...
The most common description of the electromagnetic field uses two three-dimensional vector fields called the electric field and the magnetic field.These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates.
Further analysis of this process, known as electromagnetic induction, enabled him to state the principle, now known as Faraday's law of induction, that the potential difference induced in a closed circuit is proportional to the rate of change of magnetic flux through the loop.
Continuous charge distribution. The volume charge density ρ is the amount of charge per unit volume (cube), surface charge density σ is amount per unit surface area (circle) with outward unit normal nĚ‚, d is the dipole moment between two point charges, the volume density of these is the polarization density P.
Inductance — The phenomenon whereby the property of a circuit by which energy is stored in the form of an electromagnetic field. Induction heating — Heat produced in a conductor when eddy currents pass through it. Joule heating — Heat produced in a conductor when charges move through it, such as in resistors and wires.
Low-frequency induction can be a dangerous form of inductive coupling when it happens inadvertently. For example, if a long-distance metal pipeline is installed along a right of way in parallel with a high-voltage power line, the power line can induce current on the pipe. Since the pipe is a conductor, insulated by its protective coating from ...