Why do magnets repel


A magnet is a body that attracts or repels certain other bodies. It always has a north pole and a south pole. Opposing poles attract, like poles repel. Magnets just happen in nature. For example, some rocks are magnetic. And even our earth seems to be magnetic. It not only has a geographic north and south pole, but also a magnetic one. Like all magnets, our earth is surrounded by a magnetic field. That is the effective area of ​​a magnet - i.e. the area in which it attracts or repels other magnets or magnetic bodies. This force field can be made visible.

You take:

  • a glass plate
  • 2 square timbers
  • Iron filings
  • a bar magnet

Place the bar magnet between the two square pieces of wood and the glass plate above it. Then very slowly sprinkle the iron filings on the glass plate and carefully knock on it. As if by magic, the chips will arrange themselves in a certain way in curved lines around the magnet!

What has happened there?

Due to the proximity to the bar magnet, the iron arrow shavings have all become small magnets themselves, each with a north and south pole. You have been magnetized. A magnetic field can only be detected with other magnets. By knocking, they have aligned themselves along so-called field lines. They do this because their own poles are either attracted or repelled by the north and south poles of the bar magnet. They are arranged along the field lines in the same way as the attraction in the magnetic field of the bar magnet on which it acts. An iron chip that is close to the north pole rotates - depending on the distance and thus the force of attraction - its own south pole at a certain angle to the north pole of the bar magnet because the opposite poles attract each other. Iron filings in the exact center of the bar magnet lie parallel to it because their poles are equally attracted to the poles of the bar magnet. Field lines emerge at the north pole (red) and enter at the south pole (green). We humans can only make the magnetic field visible with such a trick.

We cannot see or feel magnetic fields, neither the small magnetic field that arose in our experiment, nor the large one that surrounds our earth - in contrast to some animals: migratory birds, for example, probably know from the earth's magnetic field where to go north and Going south.