In this paper, we discuss a simple apparatus and accompanying class activity that we have developed to illustrate the Biot-Savart law. Since students in introductory electricity and magnetism courses often find this law a mathematical mystery, we feel that a simple experiment such as this will provide the students a better understanding of the concepts introduced. By collecting data from several finite segment lengths, students are able to infer the 1/r2 distance dependence of the magnetic field for infinitesimal segments and the 1/r dependence for infinite wires.
Permission has been granted by The Physics Teacher to supply this article [http://dx.doi.org/10.1119/1.2824000] for educational and research purposes. More info can be found at http://aapt.scitation.org/journal/pte. © 2008 American Association of Physics Teachers.
J.A. Phillips and J. Sanny, The Physics Teacher 46, 44 (2008); doi: 10.1119/1.2824000