1. Made by:
D. Metta K.,Gilbert V.,Firman O.
Grade 7 – Central School

2. Concepts of Magnet
 3 of metallic elements show very strong metallic
properties. They’re iron,nickel,and cobalt.

3. Concepts of Magnet
 Steel is made up by iron & carbon.
 If steel is mix up with chromium & nickel it will form
stainlees steel and can’t rust.

4. Concepts of Magnet
 A substance can be called as magnet if they’re showing
magnetic properties. (Atrract and repel each other).

5. Concepts of Magnet
 Most magnet made up by steel. There also magnet
made by mixture of magnetic material. (Ex. Alnico)
 Alnico is made by Aluminium, Nickel, Cobalt.
 They also made with copper and usually add by
titanium.

6. Concepts of Magnet
 Magnet first time discovered at ancient country called
“Magnesia”.
 Magnet also have another name. It was leading stone /
lode stone.

7. Concepts of Magnet
 There are 3 types of magnet : Horse shoes magnet, rod
magnet, bar magnet.
 Each types of magnet, have a different amount of
magnetic force.

8. The Picture of Horse shoes Magnet

9. The Picture of Rod Magnet

10. The Picture of Bar Magnet

11. Strength of the Magnetic Force
 Magnet have 2 poles: North-seeking poles and south-
seeking poles.
 If 2 same magnet pole’s bring to close each other, it’ll
repel.
 If 2 different magnet pole’s bring to close each other,
it’ll attract.

12. Strength of the Magnetic Force
 The strongest magnetic force of the magnet is located
in the poles while the weakest part is in the middle.
 If you do an experiment by attract paper clips to
magnet, the paper clips will have the magnetic force.
This called induction.

13. Behaviour of Magnets
 Magnet can attract any magnetic materials.
 Non-magnetic materials can’t attract or repel other
substance.
 Magnetic force can pass through the paper and any
other thin substance.
 Some thick substance, not let magnetic force to
pass.(ex: steel sheet)

14. Compass
Compass have 2 poles 1 north pole and 1 south
pole.Compass always show north and south except a
piece of magnet is bring near the compass.

15. Practical

16. Magnetic field
 The picture above is a picture that showing a
experiment by compass.
 If you pointed the north arrow to the north bar
magnet it will be south arrow that pointed.
 You can track the magnetic field by moving the
compass to the south pole it will make a magnetic field
pattern.

17. Practical

18. Natural magnet
 If you see the picture above it was a natural magnet.
 You can make it by make a 1 piece of iron into a
magnet. Then put it in the stereofoam put water in the
tray.
 Final steps put the magnet on the water.

19. Practical
Do not put iron fillings to the magnet directly of the magnet will be
hard to be clean.

20. Practical
This is magnetic field that make by iron fillings.

21. Magnetic domain
 Inside a magnet that are properties called domain.
 Unmagnetised material domains are arranged in
random.
 Magnetised material domains are arraged in lines.

22. Magnetic domains
 Unmagnetised material cannot attract things but can
be attract by a magnet.
 Steel are hard to make to be magnet but it was
magnetically hard and hard to lose it’s magnetical
properties.
 Iron are easy to make as a magnet but it was
magnetically soft and easy to lose it’s magnetical
properties.

23. Magnetic field
 The region that a magnet can attract magnetic things
is called magnetic field.
 Put a paper on a magnet. Then put iron fillings on the
paper and you will see a line pattern on the paper it
called magnetic filled.
 This experiment also prove that the further the
substance the magnetic force attract the substance is
reduce.

24. Magnetic field
 Magnetic force flow from north pole to the south pole.
 Actually north pole is the south pole of the earth and
south pole is the north pole of the Earth.

25. In science
 North pole is called magnetic north pole.
 South pole is called magnetic south pole.

26. In geography
 North pole is called geographic north pole.
 South pole is called geographic south pole.

27. The solar wind
 Solar wind form by a billion sun particle.
 This can interrupt the communication of the Earth.
 Solar wind make a beautiful light.(Aurora borealis and
aurora australis.)

28. Electromagnet
 If you put a iron into a wired and turn on the
electricity and make the iron into magnet.
 This concept also be use in scrap yard.

29. Electromagnet
 A wire is put around the iron bar.
 Electricity turn on and will make a powerfull magnet.
 The reason we not use steel is because it cannot be
turn off.

30. Reed Switch
 Make of a tube and 2 spingy metal.
 The tube fill with gas instead of air because not
corrode.
 When a magnet in the door is be peut away(the door
is open) It will make the springy metal have a magnet
because there is no magnet neutralise the effect of
magnet on the door frame.
 As the springy metal become magnet it will connect
the circuit and ring the buglar alarm.

31. Electric bell
 When a switch is press it make the electromagnet turn
on and attract the metal armature and springy metal
screw.
 As they attracted the circuit are broken and lose the
magnetism and ring the gong.

32. Thank you