MUTUAL IMPEDANCES OF PARALLEL WIRES 



519 



centrated in the axis, and the proof also utilizes the reciprocity relation 

 for the mutual impedances in the two directions between the two 

 wires involved; thus/ 



Zab — Zab' = Zb'a — Zb'A' = Za'H', 

 Zba = Zba' — Za'b — Za'B' — Zb'A'- 



The statement at the beginning of this paragraph is thus proved. 



PART II 

 Mathematical Theory and Calculations 

 The theoretical investigation of the self and mutual impedances per 

 unit length of two long parallel pairs of wires in space is an application 



l3=-l2 \ l2 



Fig. 4 — Cross-sectional diagram of 4-wire sjstem. 



