How can the magnetic fields be observed?

Magnetic fields are not visible but are responsible for attracting metals containing ferrous and ferromagnetic elements. By taking this property into account, their effect can be "made visible" and thus the presence of these fields is confirmed.

The materials needed to carry out the experiments are:

• Magnets.
• Steel scouring pads, gold-plated or copper scouring pads are not suitable and any size can be used, but if it is fine the result will be better.
• Bottle full of water.
• Scissors.
• Adhesive tape.

What to do?

Cut the scouring pad into very small pieces with the scissors.

Experiment 1

1.- Stick the magnets with the different poles facing each other on both sides of the bottle with adhesive tape.

2.- Gently pour the steel fibres of the scouring pad inside the bottle with the baby oil.

3.- You will observe that some of the fibres are attracted by the magnets forming a three-dimensional (3D) figure. The magnetic field lines connect the two magnets from the north pole of one magnet to the south pole of the other magnet.

Experiment 2

1.- Stick the magnets with equal poles facing each other on both sides of the bottle with adhesive tape.

2.- Gently pour the steel fibres of the scouring pad inside the bottle with the baby oil.

3.- It will be observed that some of the fibres are attracted by the magnets. The magnetic field lines, in this case, do not connect between the two magnets.

Another experiment is to use different types of bottles or magnets to make different shapes.