9 2 



ELEMENTS OF ELECTRICAL ENGINEERING. 



induced in every turn which is under the pole faces. Fig. 72 

 is a diagram, similar to Fig. 18, in which the circle represents the 

 endless circuit formed by the windings on the ring armature. 

 The arrows in Fig. 72 show the directions of the electromotive 



Fig. 71. 



forces induced in the various turns of wire on the armature, and 

 the lengths of these arrows are intended to show roughly the 

 relative values of these induced electromotive forces. 



Figs. 71 and 72 show the state of affairs when the current 

 in the armature windings is small. When the armature current 



Fig. 72. 



is large, the trend of the magnetic flux is altered from that shown 

 in Fig. 71 to that shown in Fig. 73, and the electromotive forces 

 in the various turns are altered from what is shown in Fig. 72 to 

 what is shown in Fig. 74. 



