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BELL SYSTEM TECIIXICAL JOURNAL 



with varying dH/dl. The specimen used was a cyhnder of 81 per cent 

 Ni permalloy, 60 cm. long and 0.1 cm. in diameter, and was placed in a 

 magnetic yolk. Its hysteresis loop, as shown in Fig. 11, has an 



8700 



B 



-0.2 

 I'ig. 11 — A hysteresis loop of permalloy containing 81 per cent nickel. 



unusual slope, 225,000 at 5 = 0. This gives X2 = .055 sec. From 

 this series of curves the straight line shown in Fig. 12 was obtained, for 

 which Xj + X> = 0.314 sec. By another set of loops in which the 



08 



01 



.02 



05 



.03 .04 



dH/dt 

 Fig. 12 — The change in apparent lie with varying dlljdl 



.06 



.07 



