Since their discovery, man has discovered many applications for magnetic and electromagnetic phenomena. Whether for applications as simple as a magnet on the refrigerator or as complex as magnetic resonance, we often unknowingly use these phenomena in our daily lives. Here are a few examples.
Everyone has used a magnet to post a memo on the refrigerator or to place a poster on the classroom board. However, the use of magnets and magnetism extends far beyond the display of paper.
Compasses also rely on magnetism to function. Actually, the needle of a compass is a magnet that has been cut into an elongated shape and placed on a pivot. This magnet simply needs to orient itself in the Earth’s natural magnetic field to indicate the direction of the planet’s north.
Magnetism can also be the source of spectacular phenomena. The aurorae borealis, for example, are a consequence of the Earth's magnetic field. It is also believed that birds have the ability to detect the Earth's magnetic field, which allows migratory birds to navigate during their long journey.
In addition, it is possible to "levitate" a small magnet that is repelled by a surface. This repulsive force between the magnets is increasingly used to reduce the friction between surfaces. In addition, some very high speed trains no longer use conventional rails, but rather magnets to reduce friction.
When an electric current is passed through a wire wound into a coil, it creates a magnetic field that can be put to good use. These coils of wires that act like a magnet when electric currents flow across them are called electromagnets. The image below shows an electromagnet lifting scrap metal.
For example, all electric motors operate with electromagnets. The image below provides a look at how electric motors are designed. It is interesting to observe the way in which the copper wires (in orange) are wound inside this motor.
Finally, magnetism makes it possible to create spectacular images of the interior of our body. This technology is called magnetic resonance imaging or MRI. Using magnetism, it allows us to visualize the inside of our body and thus detect abnormalities, should there be any.
