Which of the following is not the application of eddy current?
(a).induction furnance
(b).magnetic furnance
(c).speedo.eter
(d).A.C generator

When an alternating magnetic field is applied to a magnetic material an emf is induced in the material itself according to Faraday’s Law of Electromagnetic induction. Since the magnetic material is a conducting material, these EMFs circulates currents within the body of the material. These circulating currents are called Eddy Currents. They will occur when the conductor experiences a changing magnetic field.

As these currents are not responsible for doing any useful work, and it produces a loss (I²R loss) in the magnetic material known as an Eddy Current Loss. Similar to hysteresis loss, eddy current loss also increases the temperature of the magnetic material. The hysteresis and the eddy current losses in a magnetic material are also known by the name iron losses or core losses or magnetic losses.

So A. C generator is not an application of eddy current.(option d)

Regards