Table of Contents
Magnetic and Electrical Separation
Volume 10 (1999), Issue 1, Pages 29-33

An Analytic Solution for the Torque Between Two Magnetic Dipoles

Hughes Space and Communications Company, P.O. Box 92919, Los Angeles 90009, CA, USA

Received 21 December 1998; Accepted 1 February 1999

Copyright © 1999 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An analytic equation describing the torque between two magnetic dipoles is derived in this paper. We assume that the dipole sizes are small compared to their separation. Based on a previously derived force calculation between two magnetic dipoles, we derive an analytic expression for the torque. Note that the derived torque decreases with the third power of the distance between the dipoles. It is also interesting to note that the torque on the first dipole is not necessarily equal in magnitude and opposite in direction to the torque on the second dipole. This is due to the torque of both dipoles about a common center of mass.