Magnetic fields

• Magnetic field


  The region around a magnet where a force acts on another magnet or on a magnetic material

  
• Magnetic field line


  An imaginary line which indicates the direction of force caused by a magnet

  
• Direction of a magnetic field

  From the north (seeking) pole of a magnet to the south (seeking) pole

  
• How magnetic field lines indicate the direction of the field

  The field lines have an arrows on them which point from north to south

  
• How magnetic field lines indicate the strength of the field


  The closer the lines, the stronger the magnetic field
• Where the magnetic field is the strongest

  At the poles
• Effect of distance on the strength of a magnetic field


  The strength of the magnetic field decreases as the distance from the magnet increases
• Magnetic field between attracting magnets

  The magnetic fields combine to produce a uniform magnetic field

  
• Uniform magnetic field


  A magnetic field that has the same strength at every point which is represented by parallel field lines

  
• Magnetic field between repelling magnets

  The magnetic fields cancel out

  
• Detecting magnetic fields


  A magnetic field is invisible, but it can be detected using a compass

  
• Iron filings


  Small pieces of iron used to show the shape of a magnetic field

  
• Plotting compass


  Small magnetic compass used to show the shape and direction of a magnetic field

  
• The Earth's magnetic field

  A magnetic field produced by the Earth's core, which is made from iron and nickel

  
• How a compass works

  The needle of a compass is a small bar magnet that points in the direction of the Earth's magnetic field