WOW ! Magnet Magic.

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WOW ! Magnet Magic

Magnetic materials are attracted by magnets
Object Made of ? Magnetic? Yes or No?

A paperclip is attracted to the ends of a bar magnet
The paperclip is made of steel. The arrow shows the force on the paperclip.

Representing forces with arrows
The magnet also is pulled towards the paperclip. The two forces are the same size and in opposite directions.

2 magnets These ends attract These ends push apart – (repel)
There are two sorts of magnetic poles.

Making a compass N S When a magnet is hung up one end will point North. so it lines up North/South The same end always points North The end that points North is called the north seeking pole

The Earth is a magnet

A compass uses a tiny magnet which can swing round.

NORTH POLE The Earth is a magnet

Using a compass to find directions
A compass needle always points to the Earth’s North Pole. Some birds use the Earth’s magnetism to find directions.

A magnet has a north pole and a south pole. S N

The north pole attracts the south pole of the other magnet.

The north pole repels the north pole of the other magnet.
You can feel the magnets pushing apart. This is called repulsion Note - south poles also repel each other

Now for some games!

Something very new ! A computer that will stay booted up when you switch it off – it will be on sale in a few year’s time. It will have memory called MRAM and use special magnets ! (Magnetoresistive Random Access Memory)

What have we learned? Magnets will attract magnetic materials
iron and steel Magnets have two sorts of poles north and south Magnets repel each other as well as attract similar poles repel opposite poles attract A compass is a little magnet The Earth is like a magnet compasses are used to find directions Special magnets are used in computers

Magnets are used in lots of ways

It moves ! A motor causes movement.
An electric current and a magnetic field can make a simple motor. magnet + electric current  movement

Spot the motors Can you think of other examples?

Very tiny motors can be made
When the drawer for a CD opens and closes a tiny motor makes it move A tiny motor moves the camera lens when the camera is switched on Many small toys have motors in them robots, Artificial limbs can use tiny motors to act like muscles

Magnets are amazing ! Magnets + electric currents make things move !