ril. II 'ii viFi'i.-M M"n>N II 



it is now pawing from the line ; hut tin- direction of 

 n nml therefore tin- induced tension art* reversed. 



/ V 

 This we when the load in greater than 111 . 



thus causiii._' th< dynamo t<> turn backwards; work is th.-n 

 being done on tin- dynamo. as in the case of the generator. 

 bnt all the energy, inrlmlinir that from tli- line, goes in 

 heating the resistance. 



The three cases can be stated tin; 



() r/i'ssr'/i' + <v . . . motor. 

 (ft) efssfK I' . . generator. 

 . . . 



The rate of supply and expenditure of energy in the 



catM here enumerated is shown graphically in Fitr. I 1 . 



The distance ok is taken to represent tin- teniuon of the 



and nb represent** the current for no motion. - 

 the line watt- is tin* product of the tension of tin* line and 

 the curn-nt. tin* fonnr being constant, distances measured 

 vertically fn>i inv rr| indent thr lino watt 



different currents; thun at > the lim- watts is nothing. 

 while at h it is //; and for all current- the lim watts for 

 any current is given by tin- onlinate int-ri pt. ,1 }\ th.- 

 straight line ad ccntinurtl both ways beyond a and '. 



The heat watta for any current will be given I y the 

 onlinate of a parabola passing through the point* .-. ./, and 

 /, where wj is one-half /.A. Tin- cnrve can also be 

 Continued iti.l.-linit.-!\ IM-VOIK! the |> mt* and </. 



Tii>- m.v haniciil wattit for any mrreut in the difference 

 n th- line watts aiul th- heat watta for points lyint p 

 between and / ; for point** to the iHt of ,i themechn 

 watts is the sum of th,. line watt* and the heat watt* 



