Trick Magnet | Auto Nuka
Introduction
Abstract
One of two apparently identical steel rods passes easily between the poles of a magnet while the other unavoidably sticks to the magnet. One is stainless steel, the other mild steel.
Principles Illustrated
Magnetic and non-magnetic materials.
Content
Video
English version
Te Reo Māori Version
Instructions
This demonstration is a lot of fun and takes only a short time to do. You’ll need similar looking mild steel and stainless steel bars and a strong magnet. We can bring this demonstration to you if you are in the Wellington area. As an alternative, we may be able to post the steel rods to you if you have a strong magnet such as the one featured in the video.
Other Information
Safety
People with pacemakers or other medical electronics should never approach strong magnets!
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Notes, Applications, and Further Reading
Eddy current drag is used to make brakes in certain applications. See for example the following exchange on physlink: eddy currents brakes . Also see a discussion of eddy currents in Wikipedia.
Credits
This teaching resource was developed by the Te Reo Māori Physics Project with support from
- Te Puni Kōkiri
- The MacDiarmid Institute
- Faculty of Science, Victoria University of Wellington
- School of Chemical and Physical Sciences, Victoria University of Wellington
- The New Zealand map shown on the poster frame above is used with permission from www.nz.com.