Magnets

Magnets

In this project we will experiment with magnets and make a compass.

What is a Magnet?

A magnet is a special type of material that can be used to attract certain materials. There are two things required to have a magnet: It must be made of a magnetic material, typically iron; and the magnetic material must be aligned.

Iron is a magnetic material. You can think of iron as having lots of little tiny magnets. If we can make all these tiny magnets align then we get one big magnet.

Bar Magnet

bar magnet showing north and south poles and field lines

A bar magnet is a piece of material in a rectangular shape that is a magnet. It has a north pole at one end and a south pole at the other. Magnetic field lines are drawn from the north pole to the south and indicate the direction another magnet would face if put on this line. The arrow indicates that the north end of another magnet would point to the south pole of this magnet.

Disc Magnet

disc magnet showing north and south poles and field lines

Not all magnets are in the bar shape. They can be just about any shape. Above, we have a disc magnet. Similar to the bar magnet, a disc magnet has one side as a north pole and one side as a south pole, with magnetic field lines going from north to south.

How to make a magnet

There are two conditions required for a magnet:

  1. it must be made of magnetic material
  2.      - and -

  3. that material must be aligned

We can find magnetic material by testing if it is attracted to a magnet. Now, take some paper clips and hold them up to the magnet. What do you think is going to happen? If you said that the paper clip will prove to be magnetic, then you're 100% right!

We can align the magnetic material by putting it in a magnetic field. We do this by touching it to our magnet. Sliding the magnet against it a few times in the same direction will do the trick.

You can test the magnet you just made by seeing if it will now attract other paper clips. It should, but it is a very weak magnet.

The Compass

Imagine you were deep in the forest, and you could have one tool to help you find out which way you were going. What tool would you bring?

A magnetic compass is just a magnet that is allowed to spin freely so that it can align with the magnetic field lines. We can make a simple compass by floating our paper clip on water. The water acts as a low-friction environment for the paper clip to move in. When placed in this type of environment, the magnetic paper clip automatically aligns itself with the Earth's poles. Pretty cool, huh?

a homemade compass points north

earths magnetic field showing north and south poles and field lines

Activity

Take a magnet around the house and test it on different metals to determine which metals are ferrous (meaning, which metals have some iron in them) and which are not.

STEM Education Standards

  • STEM Science StandardMagnetism
    Students will recognize that magnets have two poles, North and South. An invisible magnetic field exists. Opposite poles attract, like poles repel. The earth is a magnet, a compass needle is a magnet. Students be able to test to determine which materials are magnetic. Students will identify the two requirements for a permanent magnet, material and alignment.
  • STEM Engineering StandardMaterials, and procedures
    Through building a compass students will identify the proper materials and tools to complete a project following a procedure.