Explain Eddy currents.
Eddy currents: Magnetic materials placed as in alternating magnetic fields have eddy currents also induced in them. It is because the material is subjected to rate of change of flux linkages and change in accordance along with Faraday's Law of electromagnetic induction, emfs are produced in the material causing currents, termed as eddy currents, to flow in the material. Such currents cause loss of energy. It results in the heating up of the material. Loss of Eddy current is proportional to the square of the frequency and the square of the thickness of the material and its inversely proportional to the resistivity of the material. So as to reduce this eddy currents loss thin sheets termed as laminations are used instead of solid core.