Question

What are eddy currents ?
How are eddy currents reduced in metallic cores ?
State two uses of eddy currents.

Answer 1

Eddy currents are currents which circulate in conductors like swirling eddies in a stream. They are induced by changing magnetic fields and flow in closed loops, perpendicular to the plane of the magnetic field. They can be created when a conductor is moving through a magnetic field, or when the magnetic field surrounding a stationary conductor is varying.

In order to reduce the eddy current loss, the resistance of the core should be increased. In other words, low reluctance should be retained.

In devices like transformers, the core is made up of laminations of iron. ie,the core is made up of thin sheets of steel, each lamination being insulated from others.

Two uses of eddy currents are:

(a) heat generation

(b) used in house hold current meters to measure power consumption.