Influence of geometric factors on the polarity of a remanent magnetization

The polarity, as well as the intensity of the remanent magnetization induced in a shaft by rotation in the field from a dipole source, is shown to depend on the ratio of shaft radius to the effective gap between the shaft and the dipole source. Moreover, while a real magnet is also shown to act as a single dipole source, its effective gap is greater than the physical gap by a factor dependent on the dimensions of the magnet. Experimental results support the analytic proof of the influence of these geometric factors.