Lenz's law
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Lenz's law tells the direction of a current in a conductor loop induced indirectly by the change in magnetic flux through the loop.
Scenarios a, b, c, d and e are possible. Scenario f is impossible due to the law of conservation of energy. The charges (electrons) in the
conductor are not pushed in motion directly by the change in flux, but by a circular electric field (not pictured) surrounding the total magnetic field
of inducing and induced magnetic fields. This total magnetic field induces the electric field.
Lenz's law states that the direction of the electric current induced in a conductor by
a changing magnetic field is such that the magnetic field created by the induced
current opposes changes in the initial magnetic field. It is named after physicist Emil
Lenz, who formulated it in 1834. [1]
It is a qualitative law that specifies the direction of induced current, but states nothing
about its magnitude. Lenz's law predicts the direction of many effects
in electromagnetism, such as the direction of voltage induced in an inductor or wire
loop by a changing current, or the drag force of eddy currents exerted on moving
objects in a magnetic field.
Lenz's law may be seen as analogous to Newton's third law in classical mechanics [2]
and Le Chatelier's principle in chemistry.
[3] [4]
Definition[edit]
Lenz's law states that:
The current induced in a circuit due to a change in a magnetic field is directed to
oppose the change in flux and to exert a mechanical force which opposes the
motion.
Lenz's law is contained in the rigorous treatment of Faraday's law of induction (the
magnitude of EMF induced in a coil is proportional to the rate of change of the
magnetic field), where it finds expression by the negative sign:
[5]
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This article needs additional citations for verification. Please help improve this article by adding
citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Lenz's law" – news · newspapers · books · scholar · JSTOR (October 2017) (Learn how and when to
remove this template message)
Lenz's law tells the direction of a current in a conductor loop induced indirectly by the change in magnetic flux through the loop.
Scenarios a, b, c, d and e are possible. Scenario f is impossible due to the law of conservation of energy. The charges (electrons) in the
conductor are not pushed in motion directly by the change in flux, but by a circular electric field (not pictured) surrounding the total magnetic field
of inducing and induced magnetic fields. This total magnetic field induces the electric field.
Lenz's law states that the direction of the electric current induced in a conductor by
a changing magnetic field is such that the magnetic field created by the induced
current opposes changes in the initial magnetic field. It is named after physicist Emil
Lenz, who formulated it in 1834. [1]
It is a qualitative law that specifies the direction of induced current, but states nothing
about its magnitude. Lenz's law predicts the direction of many effects
in electromagnetism, such as the direction of voltage induced in an inductor or wire
loop by a changing current, or the drag force of eddy currents exerted on moving
objects in a magnetic field.
Lenz's law may be seen as analogous to Newton's third law in classical mechanics [2]
and Le Chatelier's principle in chemistry.
[3] [4]
Definition[edit]
Lenz's law states that:
The current induced in a circuit due to a change in a magnetic field is directed to
oppose the change in flux and to exert a mechanical force which opposes the
motion.
Lenz's law is contained in the rigorous treatment of Faraday's law of induction (the
magnitude of EMF induced in a coil is proportional to the rate of change of the
magnetic field), where it finds expression by the negative sign:
[5]
