27 



rectangular position. The effective elec- 

 tromotive force which produces the cur- 

 rent I, through a resistance having no 

 self-induction, may be represented by a 

 length O E drawn to the same scale as 

 O L, and since the effective electro- 

 motive force must be the resultant of the 

 induced electromotive force and the 



electromotive force of self-induction, the 

 former can be found by constructing the 

 parallelogram OLE E<, the line O E* 

 giving the induced electromotive force 

 both as regards magnitude and position. 

 If the length O R represents- the elec- 

 tromotive force lost on account of the 

 resistance of the armature, the remaining 



