Page 469 - Basic Electrical Engineering

5

Electromagnetism and Magnetic Circuits

TOPICS DISCUSSED

Magnetic fields
Types of magnets
Concept of magnetization
Magnetization curve
Magnetic saturation
Hysteresis loss and Eddy current loss
Series and parallel magnetic circuits
Analogy of magnetic and electric circuits
Magnetic leakage and fringing
Lifting power of an electromagnet

5.1 MAGNETS AND MAGNETIC FIELDS

Magnetism plays an important role in the field of electrical engineering.
Construction of almost all electrical gadgets, equipment, and machines are

done using the properties of magnetism, like in transformers, electrical
rotating machines, i.e., generators and motors, relays, cutouts, electrical bells,

etc.
The word “magnetism” originated from the city of Magnesia (now called
Manisa in Turkey) where iron ores were discovered which had the property

of adhering to each other in lumps.
Magnets show the property of magnetism. Magnets are of two types, viz

permanent magnets and electromagnets. Magnets attract all ferromagnetic