089 – Magnetization in the earth’s magnetic field

Introduction to:

Magnetism, static magnetic field

Material:

• Radiator / water pipe, oriented vertically (ferrous / ferromagnetic)/ any large object that is ferromagnetic and has not been moved for a long time in the Earth’s magnetic field
• magnetic needle / compass

Execution:

• The magnetic needle can be used to show that the object has a magnetic south pole at the top and a magnetic north pole at the bottom.
• This is true for places in the northern hemisphere of the Earth, and the opposite is true in the southern hemisphere.

Explanation:

• The object is magnetized in the permanent magnetic field of the Earth.
• The polarity is in line with the direction of the magnetic field lines.

Didactic potential:

• Determining the polarity is a nice thinking task.
• Pupils have to take into account that, by definition, there is a magnetic south pole at the geographical north pole of the Earth.