Magnet

Magnet

1. Natural - dug from earth's crust known as lodestone

   • Made of magnetite which is a form of iron ore.

2. Man-Made (Artificial)

3. Is an object made of magnetic material. A magnetic substance can be made into a magnet

4. Can pull other objects made of iron or steel

5. Points in a North-South direction

6. A magnet exerts pulling force - magnetic force. Strongest part of magnet is at the ends of the magnet known as poles.

   • Whatever shapes of magnet, still have north and south poles
     • Shapes, Horseshoe, U-shaped, Rod, Bar, Ring, Button
   • Poles of magnet - N-Pole or S-Pole
     • Like poles - N-Pole & N-Pole OR S-Pole & S-Pole. They repel each other
     • Unlike poles - N-pole & S-pole. They attract each other

7. Magnetic Force - can pass through non magnetic object such as glass, paper, plastic and water

   • Strongest at its poles and weakest at the centre of magnet
   • Strength depends on : 1) distance between the magnet and object; 2) how magnetic the magnet is; 3) weight of object.
   • Magnet force, is felt outside the magnet - called magnetic field

8. Strength of Magnets

   • Made of iron or steel are not strong
   • Made of steel or mixtures of cobalt and nickel do not lose magnetism easily. Known as permanent magnets
   • Made of Iron tend to lose magnetism easily