This topic explores the key concepts of magnetism as they relate to:

  • the phenomenon of magnetism
  • magnetic forces and fields
  • a theory of magnetism.

Key concepts of magnetism

  • Magnets exert a force that can be described as a ‘push’ or a ‘pull’.
  • Magnets exert a force field that is called a ‘magnetic field’. A magnetic field is a region in space around a magnet that will exert force on another magnet or magnetic material.

  • Magnets attract materials composed of iron and nickel; these materials are described as being magnetic.
  • Magnets vary in strength, size and shape.
  • Magnets have north and south poles. The attracting power (magnetic field) of a magnet is greatest at its poles.
  • Like poles of a magnet attract; unlike poles repel.
  • Atoms are tiny constituents of matter and act like tiny magnets. In magnets and magnetic materials atoms form groups called ‘domains’, where their magnetic poles are aligned.
  • In magnets, domains align themselves (north poles are in the same directions). In non-magnetic materials domains do not align themselves magnetically.
  • Magnetic materials are made into temporary magnets by bringing them near a permanent magnet.
  • Earth can be considered to be one large magnet.
  • Temporary magnets can be made from a nail, wire and battery because an electric current produces magnetism.

Students’ alternative conceptions of magnetism

Research into students’ ideas about this topic has identified the following non-scientific conceptions:

  • Poles are only at the ends of magnets.
  • Big magnets are stronger than small magnets.
  • Larger magnets are stronger than smaller magnets.
  • The magnetic and geographic poles of Earth are located at the same place.
  • The geographic and magnetic poles of Earth are identical.