Section 6 Magnetism and electromagnetism
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.