Permanent & Induced Magnets

• Permanent & Induced Magnets

  Magnetic Materials:

  
• • Very few metals in the Periodic Table are magnetic. These include:
  • Iron
  • Cobalt
  • Nickel
  • Steel is an alloy which contains iron, so it is also magnetic
  • Magnetic materials (which are not magnets) will always be attracted to the magnet, regardless of which pole is held close to it.

  
• • To test whether a material is a magnet it should be brought close to a known magnet
  • If it can be repelled by the known magnet then the material itself is a magnet
  • If it can only be attracted and not repelled then it is a magnetic material
• Types of Magnets

  • There are two types of magnets
  • Permanent magnets
  • Induced magnets

  Permanent Magnets

  • Permanent magnets are made out of permanent magnetic materials, for example steel
  • A permanent magnet will produce its own magnetic field
  • It will not lose its magnetism
• Induced Magnets

  • When a magnetic material is placed in a magnetic field, the material can temporarily be turned into a magnet.
  • This is called induced magnetism
  • When magnetism is induced on a material:
  • One end of the material will become a north pole
  • The other end will become a south pole
  • Magnetic materials will always be attracted to a permanent magnet
  • This means that the end of the material closest to the magnet will have the opposite pole to magnets pole closest to the material
• Inducing magnetism in a magnetic material:

  
• • When the magnetic material is removed from the magnetic field it will lose most/all of its magnetism quickly