32 Messrs. E. B. Rosa and A. W. Smith on a Resonance 



Fig. 9. 



90 



SO 



60 



50 



V 

























\ 

























\ 



























\ \ * 



^ 



% 























\ n 



\ * 



\ c> 



\ % 



























Sl 























\ <* 



\Sf 



\ 

























\ 



\ v 





















\ 

























\ 



















85° 80° 



7o z 



70 c 



65° 60° 55° 

 Angle (p. 



50° 



45 c 



40° 



35° 30 c 



Second Definition of Efficiency. — Net Efficiency. 



Regarding the condenser as an instrument for storing 

 electrical energy, and one in which a certain amount of 

 energy is dissipated in the process, we may define the per- 

 centage of loss as the ratio of the energy dissipated to the 

 energy stored. The efficiency is then unity minus the loss, 

 or, in per cent., the efficiency is 100 minus the per cent, of 

 energy dissipated. This we may call the net efficiency, and 

 represent it by e. Then 



Energy Stored — Energy Dissipated 1 Energy Dissipated 

 Energy Stored ; Energy Stored 



In fig. 10, 

 I 1 r g = E 1 cos <£ = active electromotive force ; 



^-=E 1 sin <£ = wattless electromotive force, or the E.M.F. 



which charges the condenser. 

 The maximum charge of the condenser is 

 CE X sin <£, 



6 = 



