An Electromagnetic Teaching Aid

This paper describes a magnetic flux density measuring device (BMD) which is a helpful teaching aid in the study of the fundamentals of electricity and magnetism. The relatively low cost of construction and the simplicity of design should appeal to the university professor who wishes to ilustrate the principles of electromagnetic interaction with a demonstration, but is limited budgetwise and time-wise. The device is actualy used in calculating the force on a current carrying conductor in a magnetic field. Further algebraic manipulations yield the data for plotting a B-H magnetization curve for the ferromagnetic material used in the core. In an attempt to make the information given more readily useful, an example of the experimental procedure used at the University of Southwestern Louisiana is included. Part I describes the procedure for obtaining the data for plotting the B-H curve. Part I illustrates the quantities which determine the direction of the force on a current carrying conductor in a magnetic field and the property of residual magnetism. To reduce the somewhat time-consuming routine calculations required to obtain the data for plotting the B-H curve, a sample digital computer program is included which will perfonn this task.