Magnetic fields

• Entry Level Certificate
• Learning objectives


  How to draw the magnetic field around a magnet<|>How to identify where the magnetic field is strongest<|>What happens when the poles of magnets are brought close to each other
• Magnets


  • Can exert forces on other magnets and magnetic materials
  • Forces act at a distance
  • Examples of non-contact forces
• Magnetic metals


  • Iron
  • Steel
  • Cobalt
  • Nickel
• Not all metals are magnetic
• The force of attraction is stronger closer to the magnet


  Magnetic force is stronger at a shorter distance
• Iron filings are small pieces of iron
• Iron filings


  Used to show the magnetic field around a magnet
• Magnetic field lines


  Lines that show the magnetic field around a magnet
• The field lines are much closer together at the ends of the magnet
• Poles of the magnet

  Ends of the magnet where the force is stronger
• Field lines point from the north pole of the magnet to its south pole


  Direction of magnetic field lines
• When you put the poles of two bar magnets near each other, two things can happen
• Possible outcomes when poles are near each other

  • Attract
  • Repel
• Like poles


  Will repel each other
• Unlike poles


  Will attract each other
• The force attracting or repelling the poles is a non-contact force
• The magnetic force is strongest at the poles
• Magnetic forces


  Example of non-contact forces
• Attracting and repelling


  What happens when poles of magnets are near each other
• Investigate what happens when you put a magnet near another magnet
• Investigate the attraction of magnetic materials to a magnet
• Magnetic field shape


  Describes the arrangement of the magnetic field between poles
• Figures 3 and 4 show what is happening to the magnetic field when the poles of two bar magnets are next to each other
• Magnetic field pattern


  Shape of the magnetic field between a north pole and a south pole<|>Shape of the magnetic field between two north poles
• Choose the correct words from the box to complete the following sentences
• Magnetic forces are an example of forces
• The magnetic force is strongest at the north pole
• If you bring a north pole near another north pole

  The magnets will repel
• If you bring a south pole near a north pole

  The magnets will attract
• If you bring a south pole and a south pole together

  The magnets will repel
• Draw the magnetic field pattern around a single bar magnet
• Mark with a cross one of the points where the magnetic field is strongest
• How do you know the force is strongest here?