Magnet (2007)

A magnet can attract objects made of steel, iron, nickel and cobalt.

The pull of a magnet is called magnetism. The objects that can be attracted are called magnetic objects.

A magnet cannot attract non-magnetic objects.

Only magnets can repel magnets. The only way to test if an object is a magnet, is when it repels.

Lodestones are natural black stones that attract iron materials.

The pull of magnets can pass through some non-magnetic objects such as wood, glass and water.

There are 2 poles on a magnet, regardless of the shape and size. A freely hanging magnet always stops in a north-south direction.

Like poles (N-N or S-S) repel each other.

Unlike poles (N-S or (S-N) attract each other.

Uses of magnets:

1. Separate magnetic substances from other materials.

2. In appliance and toys. Example, telephone and electric bells.

3. Telling direction. Compass.

4. Holding objects. Example, refrigerator, magnetic pencil case and the door stopper.

Ways to make temporary magnets:

1. Touch Method. When a paperclip is attracted to a magnet, the paperclip becomes a temporary magnet because it can attract other paperclips. Once the magnet is removed, the paperclip will lose its magnetism.

2. Stroking. Use a magnet to stroke a magnetic object eg. iron bar. Stroking must be done in one direction, from one end to the other end. To make a stronger temporary magnet through stroking, you can increase the number the strokes and also use a stronger magnet.

3. Electrical Method. Use batteries attached to a wire and coil the wire around the magnetic object. The magnetic object becomes a magnet only when the electricity is switched on. To make a stronger electromagnet, you can increase the current (use more batteries and use stronger batteries) and increase the number of coils around the magnetic object.

Ways to demagnetism a magnet: Hit, Heat and Hammer