Discovering the laws of magnetic field lines

The magnetic field is the agitation that a magnet produces in the region that surrounds it, it is represented by field lines that start from the outside of the magnet from the north pole to the south pole, and from its interior to the reverse, from the south pole to the north . That is, the lines indicate how strong the field is and how far its action reaches, the closer they are together, the stronger the magnetic field and the surface occupied by these lines is the area where there is a magnetic field.

The lines are imaginary, but are used to represent the generated field; they are lines that do not intersect, they are separated from each other and from the magnet, tangentially to the direction of the field at each point. This route of the lines of force is the magnetic circuit and the quantity that forms it is called the magnetic flux.

Magnetic field lines pass through all substances, but not all behave in the same way, differentiating between ferromagnetic materials, paramagnetic materials and diamagnetic materials. Magnetic field lines do not start or end anywhere, they always form closed curves and continue inside a magnetic material (although we don’t always draw them this way).

In the real world, we can visualize field lines quite easily, most commonly by spreading iron filings around a surface close to something magnetic. Each particle of the filing behaves like a small magnet with a north pole and a south pole, filing particles naturally separate from each other because like poles repel each other. The result is a pattern similar to field lines. While the general pattern will always be the same, the exact position and density of the filing lines depend on how your particles fall, their size, and their magnetic properties.

If you can, with great caution at home, let’s perform the following experiment.