Wave-trains through a Conducting Dielectric, 339 



The curve (1) for b corresponding to a non-conducting 

 plate would be the same in both cases. The curves (3) corre- 



—9 



sponding to a plate of conductivity *01xl0 * are shown 

 together in fig. 7. b is at first greatest for the damped 



Fig. 7. 

 Comparison of the values of " b '' for damped and undamped wave-trains. 



05 



\dicleciric \constunb of plate 



11 I'l 



— undamped. 



31 



41 51 



■ dam- od. 



(51 71 81 



y = 54°44' 8". 



.-9 



Conductivity of plate = -01 x 10 . Wave-length in either case = 100 cms. /3 X = 1. 



wave-train, but as the dielectric constant is increased this 

 ratio is reversed. Physically speaking, this has very little 

 meaning : any actual method would measure the energy of 

 the reflected ray, and it has been shown * that the energy is 

 a function of the phase-change, the phase-change being itself 

 a function of the rate of damping of the wave-train. Taking 



Fig. 8. 

 \^ for damped and undamped wave-trains. 



1 11 21 



Conductivity -OlxlO- 9 . 



41 51 



X 1 = 100 cms. 



(31 71 8 



X = 54° 44' 8". 



the phase-changes, i|r, first, I calculated them for the steady 

 ray, for the damped ray with which we are dealing, and the 



conductivity *01 X 10 . The results are given together in 

 fig. 8. For the lower values of the dielectric constant, ^ for 



Equation (70). 



