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. Theyre 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 cant rust. 4. Concepts of Magnet A substance can be called as magnet if theyre 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 poles bring to close each other, itll repel. If 2 different magnet poles bring to close each other, itll 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 cant 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 its magnetical properties. Iron are easy to make as a magnet but it was magnetically soft and easy to lose its 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