Question

Mention any two advantages of eddy currents in practical application.

Answer 1

Hint: Eddy currents (also known as Foucault's currents) are electric current loops causing a magnetic field in the conductor, as provided by Faraday's law of induction, inside the conductor's system. Currents of eddy pass through the cables in closed loops opposite to the magnetic field on planes. This can be caused by a time-varying magnetic field, e.g. an AC magnet or transformer, or by relative motion between a magnet and a neighbouring conductor in the surrounding stationary conductors.

Complete step-by-step solution -
Through the rule of Lenz, an eddy stream produces a magnetic field, which opposes the alteration of the magnetic field, and eddy currents react to the magnetic field source. A near-by conductive surface, for example, may exert a drag-force against the motion of a traveling magnet owing to electric currents caused by the shifting magnetic field on the surface. This influence is due to eddy current brakes, which are used for shutting off spinning equipment rapidly. The current that passes through the conductor's resistance often discharges energy into the material as heat.
Practical applications of the Eddy current-
a). In the breaks of trains- The brakes expose the metal wheels to a magnetic field that creates currents in the wheels while braking. The magnetic motion of the distributed force with the eddy currents slows down the spokes. The faster the wheels turn, the greater the impact, which reduces the brake force as the train speeds down, resulting in a smooth stopping movement.
b). The induction motor can be used for spinning the rotor by the eddy currents. Within a spinning magnetic field, a metal cylinder(or rotor) induces eddy currents. Such currents aim to minimize relative motion, in line with Lenz 's rule, between the cylinder and the surface. Then, the cylinders continue to rotate in the field direction. It is the induction process theory.

Note: Eddy current inductors, transformers, electric motors and turbines and other AC equipment trigger energy loss, which involves different constructions, for instance laminated magnetic cores and ferrite cores. In induction heating furnaces, and machines, eddy currents are often used to heat artifacts and to locate cracks and defects in metals by means of eddy-current test devices.