5H10.30-Magnetic field lines around a magnet


Description: This demo shows the magnetic field lines of a magnet on the overhead projector.


  • bar magnet
  • Plastic container of oil and iron filings
  • Overhead Projector
  • Electric Magnetizer

Setup Procedure:

  1. Use the electric magnetizer to magnetizer the bar magnet.
  2. Place on the overhead projector and focus.

Demonstration Procedure:

  1. Turn the projector on.
  2. Place the bar magnet underneath the plastic to visually show the direction of magnetic field lines. You may need to shake the apparatus a little to get the filings to align.

Note: The array of arrows (5G20.30) works better visually.
When using the iron filings in oil, its works better to shake it like an Etch A Sketch and place the magnet underneath.