Magnets

• The poles of a magnet are the places where the magnetic forces are strongest
• Two like poles repel each other
• Two unlike poles attract each other
• Attraction and repulsion between two magnetic poles are examples of non-contact force
• A permanent magnet produces its own magnetic field
• An induced magnet is a material that becomes a magnet when it is placed in a magnetic field
• Induced magnetism always causes a force of attraction
• When removed from the magnetic field an induced magnet loses most / all of its magnetism quickly
• The region around a magnet where a force acts on another magnet or on a magnetic material is called the magnetic field
• Magnetic materials include

  • Iron
  • Steel
  • Cobalt
  • Nickle
• The force between a magnet and a magnetic material is always one of attraction
• The strength of the magnetic field depends on the distance from the magnet
• A magnetic field is strongest at the poles of the magnet
• The direction of a magnetic field line is from the north pole of a magnet to the south pole of the magnet
• A magnetic compass contains a small bar magnet
• The Earth has a magnetic field
• A compass needle points in the direction of the Earth’s magnetic field
• To plot a magnetic field pattern with a compass the compass must be places at the north pole of the magnet and a cross drawn at the north of the compass. This pattern should be followed until the line reaches the south pole
• If a compass is held away from any magnets the needle always points in the north south direction