Induction Motor. 163 



An experiment Avas cari'ied out to determine the power of the 

 apparatus so designed. It was found that when the apparatus was 

 generating one half horse-power the current in the field winding 

 Avas .575 amperes; since there are altogether 9440 turns this gives- 

 for magnetising current, 



5.43 X 10'' ampere turns. 



This value lies between the predicted limits, viz., 



5.38 > lO^""' and 5.86 x lO-'' as in equation (7). 



The rise of temperature of the winding was found from its resist- 

 ance, the temperature coeflicient of a sample of the wire having been 

 measured. The temperature rose 47° with all the vents in the 

 apparatus closed. Thus the apparatus realised the power for which 

 it was designed. The ventilation caused by the vents was large,, 

 and with them open the rise was much smaller. 



