Section 6 Magnetism and electromagnetism


Magnetic fields

  • Magnetic fields can be described using magnetic field lines which show the direction and strength of the magnetic force.
    • At any point in the field of a magnet, the direction of the field line is the direction of the force that would act on a N pole at that point.
    • The magnetic field lines around a magnet point from the N pole of the magnet all the way back round to the S pole.
    • The magnetic field is strongest where the field lines are closest or most dense.
  • If two magnets are placed close together, their magnetic fields will interact. This interaction produces a force that causes the magnets to move if they are free to do so.
  • You can show the pattern of magnetic field lines by sprinkling iron filings near the magnet. The iron filings arrange themselves in such a way as to show the magnetic field lines.
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