Document Type

Article

Publication Date

3-2006

Department

Physics

Language

English

Publication Title

American Journal of Physics

Abstract

An impressive demonstration of magnetism can be accomplished by placing some metal paperclips on a horizontal surface and then applying a vertical magnetic field. As the field is increased, the paperclips suddenly jump up, do a little dance, and then stand at attention. This behavior is related to the more common demonstration of paramagnetic and diamagnetic materials, which consists of hanging a small aluminum (paramagnetic) or glass (diamagnetic) cylinder horizontally in a strong horizontal magnetic field. A paramagnetic cylinder aligns its axis parallel to the applied field while a diamagnetic cylinder aligns its axis perpendicular to the field. This paper investigates these demonstrations by analyzing a magnetic spheroid in a uniform external field. Although this analysis explains the behavior of the paperclips, it predicts that both paramagnetic and diamagnetic cylinders will align themselves parallel to a uniform external field, in contrast to the common demonstration experiment.

Comments

This published version is made available on Dickinson Scholar with the permission of the publisher. For more information on the published version, visit American Association of Physics Teacher's (AAPT) Website.

© 2006 American Association of Physics Teachers

DOI

10.1119/1.2173279

Included in

Physics Commons

COinS