Measuring the magnetization of a permanent magnet

The effect of an external magnetic field B on magnetic materials is a subject of immense importance. The simplest and oldest manifestation of such effects is the behavior of the magnetic compass. Magnetization M plays a key role in studying the response of magnetic materials to B. In this paper, an experimental technique for the determination of M of a permanent magnet will be presented. The proposed method discusses the effect of B (produced by a pair of Helmholtz coils) on a permanent magnet, suspended by two strings and allowed to oscillate under the influence of the torque that the magnetic field exerts on the magnet. The arrangement used Newton's second law for rotational motion to measure M via graphical analysis.