Presentation on theme: "WOW ! Magnet Magic. 2 Magnetic materials are attracted by magnets Object Made of ? Magnetic? Yes or No?"— Presentation transcript:
WOW ! Magnet Magic
2 Magnetic materials are attracted by magnets Object Made of ? Magnetic? Yes or No?
3 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.
4 Representing forces with arrows The magnet also is pulled towards the paperclip. The two forces are the same size and in opposite directions.
5 2 magnets These ends attract These ends push apart – (repel) There are two sorts of magnetic poles.
6 Making a compass 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 N S
7 The Earth is a magnet
8 A compass uses a tiny magnet which can swing round.
9 The Earth is a magnet NORTH POLE
10 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.
11 A magnet has a north pole and a south pole. S N
12 The north pole attracts the south pole of the other magnet. S N S N S N S N
13 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 S N S N
14 Now for some games!
15 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)
16 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
17 Magnets are used in lots of ways
18 It moves ! A motor causes movement. An electric current and a magnetic field can make a simple motor. magnet + electric current movement
19 Spot the motors Can you think of other examples?
20 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 !