5G20.27 Iron Filings Domains
Magnetization of a ferromagnet
A tube filled with iron filings is magnetized and the magnetization is shown using a compass. Note: this demonstration can be shown on the overhead projector and is appropriate for large lecture halls.
-  Glass tube filled with iron filings
-  NdBFe magnet
-  Small compass
- The magnet is strong. Handle with care.
- Shake the filings into the long thin section of the tube.
- Magnetize the filings by stroking the length of the tube several times with a magnet.
- Hold the end of the tube near the compass. Note the movement of the compass needle.
- Shake the filings into the bulb end and shake several times.
- Shake the filings back into the tube.
- Hold the end of the tube near the compass. Note that the iron filings are now unmagnetized as the compass needle no longer moves.
- PIRA 5G20.27
- Don't attempt this at home!
- The magnet should be strong. A 1/2 inch diameter NdBFe magnet is used here.
If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.