152 



ELEMENTS OF ELECTRICAL ENGINEERING. 



Demagnetizing action and cross-magnetizing action. The nature 

 of armature reaction and its resolution into the two parts, demag- 

 netizing action and cross-magnetizing action, is most clearly 



Fig. 97. Undistorted field of a dynamo when 

 armature current is small. 



Fig. 98. Distorted field of a generator when its 

 armature current is large. 



Fig. 99. Same as Fig. 98, but showing motor distortion for same direction of running. 



brought out by considering a bipolar dynamo as shown in Fig. 

 100. The brushes are shown at an angular distance a ahead of 

 the line AB, which is at right angles to the axis of the field. 

 All of the conductors marked with a dot are supposed to carry 

 outward flowing current (towards the reader), and all conductors 



