An eddy current is a phenomenon caused by a moving magnetic field intersecting a conductor or vice-versa. The relative motion causes a circulating flow of electrons or current within the conductor. These circulating eddies of current create electromagnets with magnetic fields that oppose the external magnetic field (see Lenz's law). The stronger the magnetic field, or greater the electrical conductivity of the conductor, the greater the currents developed, and the greater the opposing force. This is used to great effect in movement to electricity converters such as electrical generators and dynamic microphones. Friction within the conductor, or resistance, cause a dragging effect that has been used for braking and damping. Superconductors which allow perfect, loss-less conduction create a perfect eddy current that entirely cancels the opposing magnetic force allowing magnetic levitation. Eddy currents are also the root cause of skin effect in conductors carrying AC current. Current flowing through a wire produces a magnetic field (M) around the wire. ... It has been suggested that Conductor (power engineering) be merged into this article or section. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... In electricity, current refers to electric current, which is the flow of electric charge. ... An electromagnet is a type of magnet in which the magnetic field is induced by a flow of electric current. ... Introduction Lenzs law gives the direction of the induced emf resulting from electromagnetic induction, thus: Explanation According to Lenzs law if the magnetic flux is increased then the induced emf is produced in such a way that it opposes the increase in flux i. ... Electrical conductivity is a measure of how well a material accommodates the transport of electric charge. ... Insert non-formatted text here // Headline text Bold text:Generator redirects here. ... Inside a condenser microphone. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Superconductivity is a phenomenon occurring in certain materials at low temperatures, characterised by the complete absence of electrical resistance and the damping of the interior magnetic field (the Meissner effect. ... Magnetic levitation is the process by which an object is suspended above another object with no other support but magnetic fields. ... The skin effect is the tendency of an alternating electric current to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core. ...

Eddy currents are used for braking at the end of some roller coasters; this mechanism has no mechanical wear, and produces a very precise braking force. Typically heavy copper plates extending from the car are moved between pairs of very strong permanent magnets. General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance copper, metallic Atomic mass 63. ...

Eddy currents create losses through Joule heating, and they reduce the efficiency of many devices that use changing magnetic fields such as iron core transformers and alternating current motors. They are minimized by selecting core materials that have low electrical conductivity or by using thin sheets (laminations) of magnetic material. In electronics, and in physics more broadly, Joule heating refers to the increase in temperature of a conductor as a result of resistance to an electrical current flowing through it. ... Transformers - Typical electrical configurations. ... Electric motors of various sizes. ...

Use of eddy current techniques is a common method for the inspection and condition monitoring of heat exchanger tubes. A heat exchanger is a device for transferring heat from one fluid to another, where the fluids are separated by a solid wall so that they never mix. ... A tube is hollow cylindrical shape. ...

An analogous eddy current is seen in water when dragging an oar, localised areas of turbulence give rise to vortices, which persist. An oar is a tool used for Marine Propulsion. ...

Some examples of uses of eddy currents:

• Metal detectors
• Induction cooker
• Traffic detection systems
• Safety Hazard and defect detection applications