how eddy currents are created and how i can extract them.?

Answer 1

An eddy current (also known as Foucault 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 change in 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. It can also be used to induce a magnetic field in aluminum cans, which allows them to be separated easily from other recyclables. Friction within the conductor, or resistance, cause a dragging effect that has been used for braking and damping. Superconductors allow perfect, lossless conduction which creates eddy currents that entirely cancel the external magnetic field, allowing magnetic levitation. Eddy currents are also the root cause of skin effect in conductors carrying AC current.