Unit 9.1 Magnetic Field

• • each magnet has their own magnetic field
  • a magnet is something that will attract magnetic materials
  • magnetic materials include the metals such as iron, steel, nickel and cobalt
  • magnets have two poles, North (N) and South (S)
  • a magnetic field is the area around a magnet where the effects of the magnet can be detected. It surrounds all magnets.
• • the magnetic field of a magnet is the strongest at the poles
  • when a magnetic material is in the magnetic field, it will be attracted towards the magnet
  • as the magnetic material moves further away, it stops being attracted as it is out of the magnetic field region
  • the magnetic field can be detected by:
  • seeing whether a magnetic object moves because of attraction
  • use a compass which contains a magnetised needle that is free to turn. The needle will point to the direction of the magnetic field
• Magnetic Field Lines

  • 4 rules to draw the magnetic field lines around the magnet
  • the field joins opposite poles
  • the field lines go from N to S
  • lines must not touch each other
  • lines must not cross each other
  • plotting compass/compass is used to point in the direction of the lines
• Magnetic Fields Interacting

  • unlike (opposite) poles attract; like (same) poles repel
  • this force is due to the interaction of the magnetic fields from each magnet
  • Unlike Poles Interacting
  • the magnetic field lines between the two magnets are all pointing in the same direction
  • there will be a force of attraction between the magnets
  • Like Poles Interacting
  • the magnetic field lines in the space directly between these two magnets are all pointing in opposite directions
  • magnets will repel/try to move away from each other