Question

Give two uses of eddy currents?

Answer 1

Eddy currents in conductors of non-zero resistivity generate heat as well as electromagnetic forces. The heat can be used for induction heating. Theelectromagnetic forces can be used for levitation, creating movement, or to give a strong braking effect.

Answer 2

There are various uses of Eddy Current. I will mention some below.

1. ELECTROMAGNETIC DAMPING

Used to design dead beat galvanometers. Usually, the needle oscillates a little about its equilibrium position before it comes to rest. This causes a delay in taking the reading. to avoid this delay, the coil is wound over a non-magnetic metallic frame. As the coil is deflected, eddy currents set up in the metallic frame and thus, the needle comes to rest almost instantly. Thus, the motion of the “coil is damped”.

2. INDUCTION FURNACE

In a rapidly changing magnetic fields, due to a large emf produced, large eddy currents are set up. Eddy currents produce temperature. Thus a large temperature is created. Thus a coil wound over a constituent metal is placed in a field of highly oscillating magnetic field produced by high frequency ac. The temperature produced is enough to melt the metal. This is used to extract metals from ores.

3. INDUCTOTHERMY / DIA-THERMY

Eddy currents are used for deep heat treatment of the human body. Eddy currents can be used to heat the localized tissues in the human body.

4. ELECTROMAGNETIC INDUCTION

5. INDUCTION MOTOR

6. SPEEDOMETERS AND ENERGY METERS