CHAPTER IV. 

 SINGLE-PHASE CURRENTS. 



EXPERIMENT 4-A. Study of Series and Parallel Circuits Con- 

 taining Resistance and Reactance. 



I. Introductory. The object of this experiment is to acquaint 

 one with the fundamental relations between currents and electro- 

 motive forces in alternating current circuits. These relations will 

 be brought out by a study of series and parallel circuits contain- 

 ing resistance and inductance, the clear understanding of which is 

 essential for one undertaking any study of alternating currents. 

 Practically every problem in alternating currents involves or can 

 be reduced to a problem of series and parallel circuits. A study 

 of alternator characteristics (see Figs. 3-5, Exp. 3~B) is a study 

 of series circuits; the transformer (see Figs. 6-9, Exp. 5~C) can 

 be reduced to equivalent series and parallel circuits, and so, too, 

 the induction motor. This is true of nearly all types and kinds 

 of alternating current apparatus. It will be found that the study 

 of series and parallel circuits brings out the general principles 

 that are common to all alternating current problems. Such cir- 

 cuits are studied, therefore, not merely as leading up to the sub- 

 ject proper, but as actually being the subject matter of all alter- 

 nating current testing. 



Part I. contains an outline of the underlying principles of the 

 subject, which will be found discussed in detail in Bedell and 

 Crehore's Alternating Currents and in other treatises. Part II. 

 describes the tests to be made and Part III. describes the results 

 derived from them. For the convenience of the reader, some 

 paragraphs on theory are included in Part III. 



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