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In electromagnetism, an eddy current (also called Foucault's current) is a loop of electric current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction or by the relative motion of a conductor in a magnetic field. Eddy currents flow in closed loops within conductors, in planes ...
In the traditional version of eddy current testing an alternating (AC) magnetic field is used to induce eddy currents inside the material to be investigated. If the material contains a crack or flaw which make the spatial distribution of the electrical conductivity nonuniform, the path of the eddy currents is perturbed and the impedance of the ...
In fluid dynamics, an eddy is the swirling of a fluid and the reverse current created when the fluid is in a turbulent flow regime. [2] The moving fluid creates a space devoid of downstream-flowing fluid on the downstream side of the object.
Eddy currents flow in closed loops in planes perpendicular to the magnetic field. They have useful applications in eddy current brakes and induction heating systems. However eddy currents induced in the metal magnetic cores of transformers and AC motors and generators are undesirable since they dissipate energy (called core losses) as heat in ...
English: A coil transmitting current produces a magnetic field which induces a secondary magnetic field in a nearby conductor. If this is a metal surface, it causes a local circular loop of current, called an eddy current.
Cause of skin effect. A main current I flowing through a conductor induces a magnetic field H.If the current increases, as in this figure, the resulting increase in H induces separate, circulating eddy currents I W which partially cancel the current flow in the center and reinforce it near the skin.
English: Diagram of eddy currents (I, red) induced in conductive metal sheet (C) moving under a stationary magnet (N), showing the origin of the braking force The magnetic field lines (B, green) from the North pole of the magnet extend down through the sheet.
The energy in these currents is dissipated as heat in the electrical resistance of the conductor, so they are a cause of energy loss. Since the magnet's iron core is conductive, and most of the magnetic field is concentrated there, eddy currents in the core are the major problem. Eddy currents are closed loops of current that flow in planes ...