BCIT Physics Department

Demonstration Manual

Electricity and Magnetism

DEM24 - Magnetic Field


- To show the shape of the magnetic field about a bar magnet.



The magnet is positioned on the overhead projector so that its image is projected on the screen. Projection tray is placed on top of the magnet. Place the "shallow" side of projecting tray facing down over the Bar magnet. Iron filings are sprinkled on to it. The pattern of the magnetic field is formed and is projected together with magnet's image.


  1. Tap the tray when sprinkling iron filings. This produces a more distinct pattern.
  2. Do not allow iron filings to cling to the magnets directly.