Introduction

Our discussion on electrical engineering has been so far pivoted upon two major aspects. First, the electrical and magnetic field and the correlation between them. Second, the different types of electrical circuits through which a continuous flow of electric charge can be established. We by this time have acquired the knowledge that the electric and magnetic fields complement each other. They often co-exist in a material. The most obvious supposition from the above discussion is the analogy between magnetic and electric field knowing the facts of electrical circuit we can imagine the existence of magnetic circuit following the similar laws to electric circuit laws.

In the first half of seventeenth century the idea of magnetic circuit was developed. When two magnetic coils are placed in close vicinity to each other, the coils get magnetically coupled. The same flux is linked with both coils. Thus, there must be a magnetic connection between two magnetically coupled coils. The connection between the coils is certainly not via an electrical circuit. The magnetic connection is made by another circuit. There is no material link between two magnetically coupled coils. So no electron flow is practically possible. We can only think of a circuit through which magnetic flux can be flowed and linked the two coils. This circuit is named as magnetic circuit. In this chapter, we shall discuss more on different phenomena and laws of magnetic circuit.