BCIT Physics Department

Demonstration Manual

Electricity and Magnetism

DEM24.2 - Magnetic Field Projectual


- To show the shape of the magnetic field surrounding any magnet shape.


DEM24.2 - Magnetic Field Projectual


The magnet(s) are placed on the O.H. projector. The projectual is rotated in all directions to disperse the iron filings in the oil. An internal glass rod is also rolled from side to side. The projectual (projected by Mylar against scratching) is placed over the magnets and the O.H. projector re-focussed on the resulting pattern.


  1. Do not press on the projectual. Hydraulic pressure may cause the unit to leak oil.

  2. Do not leave the projectual on the hot O.H. projector for long periods. Thermal expansion of the oil may cause leaking.