218 



BELL SYSTEM TECHNICAL JOURNAL 



D.-C. Results 



The permeability n = BmjHm of the specimen is shown as a function 

 of Hm in Fig. 2, on a greatly enlarged scale in which the zero of per- 

 meability is not shown. The slope of this line gives X = 21.5 X 10~^. 



Values of ^B are plotted against // for two different hysteresis loops 

 in Fig. 3, from the area of which the energy loss W is computed. For 



Z 120 



-30 -25 -20 -15 -10 -5 5 10 15 20 25 30 



H IN OERSTEDS X 10"* 



Fig. 3 — Two hysteresis (half) loops plotted with reference to a straight line 

 through their tips. 



comparison, Rayleigh loops are shown as broken lines. By analysis 

 of the interior angles 0+ and </>_ between the AB vs. H curve and the 

 // axis at points -j- H and — // respectively, it is found that <f)+ is 

 larger than for the Rayleigh loop, and is given by the relation tan 

 4>+= nokBm, while 0_ is a corresponding amount smaller than for 



