Magnetism

• Magnets exist naturally in the form of loadstones.
• Man made magnets are made of materials such as iron, steel, cobalt and nickel.
• Magnets attract magnetic materials.
• Magnets have 2 poles: north and south.
• Opposite poles attract (north to south or south to north).
• Like poles repel (north to north or south to south).
• A freely suspended magnet shows north-south direction.
• Magnetic compasses use the Earth's magnetic field to show directions.
• Earth's magnetic field protects us from solar winds.
• The area around the magnet with magnetic force is known as magnetic field.
• Magnetic field lines begin from the north pole and end at the south pole.
• Magnetic field lines never meet or cross.
• Magnetic field lines are closer to one another where the magnetic field is stronger.
• Electromagnet: a type of magnet that had a temporary magnetic effect when electric current flows through it.
• The pattern of the magnetic field depends on the shape of the conductor.
• Right-hand grip rule

  A) current

  B) magnetic field

  
• Straight Wire magnetic fields

  
• Coiled wire magnetic fields

  
• Solenoid magnetic fields.