The custom magnets bulk fix the notes on the refrigerator, close the purses, and hold the soaps on their support. And all without glue. How is it possible and what invisible forces are at work?
A magnet always has two sides
A magnet always has two poles. And if you cut it in the middle, the two halves would in turn each have two poles.
Magnets are metals that attract or repel other metals. Iron, nickel and cobalt are metals with magnetic properties. A magnet always has two sides, called North Pole and South Pole. The two opposite poles attract each other. You can try yourself by taking two magnets. If you hold the North Pole and the South Pole side by side, magnets attract each other. But if you put the North Pole near the North Pole, they repel each other. Can you feel the forces in action? Invisible forces acting between two magnets are called magnetic forces.
Make the magnetic forces visible
The magnetic field lines go from the North Pole to the South Pole.
Magnetic forces are invisible to the human eye, and we can not feel or hear them either. The area around a magnet in which the magnetic forces act, that is to say where the magnet attracts or repels other magnetized objects, is called the magnetic field. Scientists represent the magnetic field by lines called magnetic field lines.
Make the magnetic field lines appear
Iron scrap on paper. The filings are oriented according to the magnetic field produced by the magnetic bars placed underneath.
You can reveal invisible magnetic field lines by scattering iron filings or small needles on paper. You can then put a magnetic bar under the paper and observe how the filings are distributed according to the magnetic field of the magnet. If you move the magnet slowly, you see how the filth follows the magnet magically.
How does a piece of metal become magnetic?
You can magnetize a piece of metal by rubbing a magnet in one direction.
All metals are not magnetized. This comes from the fact that the metal particles, or atoms, of which the metal is made are arranged in disorder. You can picture each of these particles as a tiny magnet. As these little magnets are in disorder, their magnetic forces are balanced, so that the piece of metal has no North Pole or South Pole. However, these particles can be ordered by passing an iron magnet on the piece of metal. The particles all turn in the same direction, the magnetic forces unite and the piece of metal is magnetized (it must be iron, nickel or cobalt). You can also try it yourself (see box below)