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ERIC Number: EJ931193
Record Type: Journal
Publication Date: 2010-Nov
Pages: 2
Abstractor: ERIC
Reference Count: 4
ISSN: ISSN-0031-9120
The Shaking Torch: Another Variation on the Inductive Force
Thompson, Frank
Physics Education, v45 n6 p575-576 Nov 2010
A recent article showed how the influx of neodymium magnets has provided striking demonstrations of the interactions between magnets and conductors. The "shaking torch" is yet another example. Many of these torches require no batteries and can be submerged in water--indeed, a light for life. In this article, the author disassembles a shaking torch to know its component parts and find out how the torch actually worked. Dissecting a shaking torch has allowed an experiment to be carried out on the "generator" of this torch. Order-of-magnitude calculations show that several volts are expected from this generator. In summary the magnet is likely to be one of the powerful neodymium magnets used in toys and the like. One would be advised to be cautious about bringing it close to heart pacemakers, identity or loyalty cards or, indeed, credit cards or any other form of magnetic memory device. (Contains 6 figures.)
Institute of Physics Publishing. The Public Ledger Building Suite 929, 150 South Independence Mall West, Philadelphia, PA 19106. Tel: 215-627-0880; Fax: 215-627-0879; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A