An Overview of Magnetic Field Lines and its Characteristics

December 01, 2020

In this blog, we will review the theory of Magnetic Fields and its basic concept. We all know that magnets exert forces on each other and its magnetic force is distributed around. Magnetic field lines are used to describe these forces around the magnet. We understand that magnets have two poles and that depending on the orientation of two magnets there can be an attraction (opposite poles) or repulsion (similar poles). We also recognize that there is some region extending around a magnet where this happens and this is explained by the magnetic field lines.

How to map a basic Magnetic Field?

Let's begin with the field lines of a bar magnet, perhaps the simplest case to analyze. In Fig.1, we can observe the magnetic field pattern of a bar magnet by scattering iron filings over it.  As the filings are scattered around the magnet, they become temporary magnets (by magnetic induction) and line up end-to-end. The filings tend to clump together around the poles of the magnet, indicating that this is where the magnetic field is strongest. The lines of iron filings give an impression of the layout of the magnetic field. We also see all field lines begin at the north pole and terminate at the south pole.


Fig 1. Iron filings create a pattern around a bar magnet

Characteristics of a Magnetic Field Lines:

The pictorial representation of magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Extensive exploration of magnetic fields has revealed a number of characteristics that help us understand them better.  Below are the important characteristics of a magnetic field: 
•    Form a continuous closed loop
•    Elastic in nature
•    Takes path of least reluctance
•    Never intersect each other
•    Has direction from north to the south pole, even though there is no actual movement

Why are Magnetic Field Lines Important?

Magnetic fields are used throughout modern technology, particularly in electrical engineering and electromechanics, and crucial for a technician to understand. Measuring Magnetic field lines helps us calculate:

  • The magnitude of the magnetic field
  • The direction of the magnetic field
  • Magnetic field intensity

We hope this has been helpful to you as a Technician or a student entering the field. If you have any questions about the Electronics or the Electromechanical Technician programs you can reach one of our Program Consultants toll-free at 1-888-553-5333 or by email at



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