June 12, 2010
by: Martin Sagendorf
This 3D Magnetic Field demonstration is actually quite easy to do. It clearly illustrates that magnetic fields are not flat (as too frequently demonstrated in the classroom).
Demonstrating a 3D Magnetic Field
This easy-to-make construction requires only four components:
- A clear plastic bottle (about 1-3/4” in one dimension) – the one illustrated below is a 12.6 fl oz ultra concentrated Joy ® dishwashing soap bottle – Note that any bottle originally containing soap or detergent will require repeated rinses to completely remove all of its original contents.
- Six 17 mm x 3 mm Neodymium ring magnets Read the rest of this entry »
June 11, 2010
by: Michelle Bertke
Simple iron filings can be used for a variety of interesting experiments and demonstrations. Magnetism is a mysterious concept that can be difficult for students to grasp. Magnetic fields are the forces surrounding a magnet that are identified by how they interact with adjacent magnets and other metal objects. While magnetic fields are ‘invisible’ they can be observed by sprinkling iron filings on a white paper with magnets beneath.
By lightly coating the surface of the paper, the magnetic field will appear as filings align themselves with the field. Different magnets, depending on their strength and shape will create varying patterns in the iron filings. A bar magnet with a distinct north and south will show characteristic lines of a magnetic field. Circular magnets may show multiple lines indicating multiple magnet fields. The stronger neodymium magnets will cause the iron filings to pile up in spikes due to the increased strength. This demonstration can lead to a discussion about magnetic fields: What they are, Where they can be found, and How they are used in the world around us. Read the rest of this entry »