WAVE PROPAGATION OVER CONTINUOUSLY LOADED WIRES 197 



solution of this problem is not an essential part of the investigation, 

 but it helps in understanding what takes place in the bi-metalhc 



conductor. 



The ratio of the currents in wire and sheath to the total current, as 

 computed from (1), is plotted in Fig. 3. It will be noted that the 

 fraction of the total current carried by the sheath becomes greater 



800 



5 

 o 



a 



s 



If) 

 Q. 

 Z 

 < 



z 

 u 



Q 



UJ 

 CC 



u 



600 



400 



200 



FOR A TOTAL CURRENT 



OF I AMPERE IN THE 



WIRE AND SHEATH 



• DIRECT CURRENT 



^ Uir\C.^ I v_-'-'r\r\ui"< I 



*M0 KILOCYCLES 



10 KC. 



2KC, 



UJ < 



O 

 UJ 



o 



UJ 



< o 



? < 



Q- J 



0.01 



0.02 0.03 



RADIUS OF COPPER WIRE- 

 CENTIMETERS 



0.04 0.045580 0.046758 



HSHEATHk- 



THICKNESS 



/ SCALE \ 

 I ENLAROEDJ 



Fig 4— Illustrating the current density throughout the cross-section of a Avue loaded 



with a continuous magnetic sheath— for direct current and 2 and 10 kilocycle 



alternating currents. (Same 19 B. & S. gauge wire as that of Fig. 3.) 



as the frequency increases. But the fraction carried by the copper 

 nevertheless remains very nearly unity at all frequencies. This 

 behavior is explained In^ the curves representing the phase angles 

 involved. These show, of course, that at very low frequencies the 



