Question

Describe the ways in which Eddy current are used to advantage.

Answer 1

Advantages of eddy currents are as follows:

(i) Eddy current brakes use the drag force created by eddy currents as a brake to slow or stop moving objects. Since there is no contact with a brake shoe or drum, there is no mechanical wear. However, an eddy current brake cannot provide a holding torque and so may be used in combination with mechanical brakes, for example, on overhead cranes.
(ii) Eddy current is used in crack detection equipment. It can be divided into high frequency instruments for finding surface breaking cracks in ferrous and non-ferrous materials and low frequency instruments for finding cracks in non-ferrous materials.
(iii) Induction furnace separates certain metals from their ores. It is done by heating the metal. The type of heating done is called induction heating. This heating can be done using eddy currents. The metal to be heated is placed in a high frequency changing magnetic field. Strong eddy currents produced will give rise to desired heating.