152 



KENNELLY— THE LINEAR RESISTANCE 



[April 24, 



(i). Consequently, the linear resistance of the double cylinder 

 system of Fig. 4 is 



r , = -cosh-^ (dl(T) =^ V absohm-cms. (32) 



TT 'IT 



where d = D/2. The resistance factor of the system is thus Y /it, 

 or double that given in column III. of the table. 



Thus, if the two cyUnders, each of radius (r = 2 cm. separated 



Fig. 4. Two equal and parallel conducting cylinders at interaxial distance 



oi D cm. 



by an interaxial distance Z>-=8 cm. in a medium of resistivity 

 p r=z 5 X io^° absohm-cms. we have c? = 4, and d/u = 2. 

 K = cosh-^2= 1.317, and the linear resistance is 



absohm-cms. 



