7.1 Permanent and Induced Magnetism, Magnetic Forces

• Poles of a magnet


  The part of a magnet where the magnetic forces are strongest
• Two magnets are brought close to each other

  They exert a force on each other
• Force exerted when two like poles of a magnet are brought near each other

  Repulsive, non-contact force
• Force exerted when two unlike poles of a magnet are brought near each other

  Attractive, non-contact force
• Permanent magnet


  Produces its own magnetic field
• Induced magnet


  Becomes magnetic when placed in a magnetic field
• Induced magnetism always causes a force of attraction
• When an induced magnet is removed from a magnetic field, it loses most/all of its magnetism
• Magnetic field


  The region surrounding a magnet where another magnet or magnetic material experiences a non-contact force
• Magnetic materials


  • Iron
  • Steel
  • Cobalt
  • Nickel
• The force between a magnet and a magnetic material is always attractive
• Moving further away from the magnet producing the magnetic field

  The magnetic field strength decreases
• Direction of a magnetic field

  • In the direction that a north pole would experience a force if placed in the field
  • From the north seeking pole to the south seeking pole of a magnet
• Magnetic compass


  Contains a small bar magnet that points in the direction of the Earth's magnetic field