Figure 4 - Normal magnetization curve.
If the coil in Figure 1 is wound around a steel core, an
electromagnet is created which allows for more efficient
magnetization.
Figure 5 - Iron core electromagnet.
When a magnet sample is placed between the poles of the
electromagnet with minimal air gap between the poles of
the electromagnet and the sample, an accurate magnetization
curve and hysteresis loop of the sample can be
generated.
Figure 6 - Electromagnet gap and test sample