How to make a magnetic compass

  • Magnetism is an invisible force that affects materials such as iron, steel, nickel and cobalt.

  • A compass can be used to detect both the Earth’s magnetic field and the field around other magnets.

  • This guide will show you how to make your own magnetic detector, a compass.

Have a go

WHAT YOU NEED: A bowl of water, cork, sewing needle and a compass.

WHAT YOU NEED: A bowl of water, cork, sewing needle and a compass.

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Why does the needle move?

The needle is being affected by the Earth’s magnetic field. One end points towards magnetic north and the other end points south. You can use a compass to check which direction each end is facing.

The Sun is in the South at about midday, so you can also check your compass is working if one end points in that direction. The other end of the needle will be pointing north, away from the Sun.

Where are compasses used?

When it is dark or foggy, ships need to know they are sailing in the right direction. A ship’s navigator uses a compass to check that they are still on course. Explorers also use a compass to help them find their way and avoid getting lost.

Where next?

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