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This field causes, by electromagnetic induction, an electric current to flow in the wire loop on the right. Electromagnetic or magnetic induction is the production of an electromotive force (emf) across an electrical conductor in a changing magnetic field .
This field causes, by electromagnetic induction, an electric current to flow in the wire loop on the right. The most widespread version of Faraday's law states: The electromotive force around a closed path is equal to the negative of the time rate of change of the magnetic flux enclosed by the path.
Electromagnetic induction was first described by Michael Faraday in 1831. [8] [9] In Faraday's experiment, he wrapped two wires around opposite sides of an iron ring. He expected that, when current started to flow in one wire, a sort of wave would travel through the ring and cause some electrical effect on the opposite side.
Eddy currents in conductors of non-zero resistivity generate heat as well as electromagnetic forces. The heat can be used for induction heating. The electromagnetic forces can be used for levitation, creating movement, or to give a strong braking effect. Eddy currents can also have undesirable effects, for instance power loss in transformers.
The electromagnetic force is one of the four fundamental forces of nature. It is the dominant force in the interactions of atoms and molecules. Electromagnetism can be thought of as a combination of electrostatics and magnetism, which are distinct but closely intertwined phenomena. Electromagnetic forces occur between any two charged particles.
For example, the voltage appearing across an inductor or coil is due to a change in current which causes a change in the magnetic field within the coil, and therefore the self-induced voltage. [ 1 ] [ 2 ] The polarity of the voltage at every moment opposes that of the change in applied voltage, to keep the current constant.
Electromagnetic induction is the production of a circulating electric field by a time-dependent magnetic field. A time-dependent magnetic field can be produced either by motion of a magnet relative to a circuit, by motion of a circuit relative to another circuit (at least one of these must be carrying an electric current), or by changing the ...
In electromagnetic waves, the skin depth is the depth at which the amplitude of the electric and magnetic fields have reduced by . [21] The intensity of the wave is proportional to the square of the amplitude, and thus the depth at which the intensity has diminished by 1 e {\displaystyle {\frac {1}{e}}} is δ 2 . {\displaystyle {\frac {\delta ...