344 Dr. J. R. Ashworth on Magnetic Hysteresis 



3. Suppose, however, that H is not ignored in equation 

 (3), then the straight line representing this equation will not 

 in general pass through the origin. 



Fiff. 3. 



Negative Field 



5 







6 



l§ 4 



\ 



7 



'II 3 



A 



8 

 3 





: V 



1 







.1 2 3 4 5 





+J 



Temperature 



Thus, at a given temperature the isothermal for different 

 fields would be obtained by tracing the points of intersection 

 of a straight line carried parallel ito itself with the curve of 

 equation (1), the slope of the line being determined by the 

 temperature. 



For example, let a strong field be applied, then the inten- 

 sity takes some high value F (fig. 3) ; as the field is reduced 

 to zero, by the straight line through F being moved parallel 

 to itself until it passes through the origin, the intensity falls 

 to D. The point D gives the residual intensity of magne- 

 tization. Let the field now be carried to increasing negative 

 values, which means that the straight line must be moved 



