Description: A sealed glass tube filled with iron flings may be used to demonstrate magnetization of a ferromagnet.

Shake the filings into the long thin section of the tube. Magnetize the filings by stroking a magnet the length of the tube several times. Use a zippy magnet, a 1/2 inch diameter NdBFe magnet works well. Demonstrate that the filings are magnetized by holding one end near the compass. Shake the filings into the bulb end, shake several times, then shake them back into the tube. Demonstrate that the sample is now unmagnetized.

Cautions:

Concepts demonstrated:

Setup Time: Short

Difficulty/Commitment: Straightforward

Visibility: use on the overhead projector

Related demonstrations:

References: PIRA 5G20.27