POWER AND POWER-FACTOR. 



61 



The following experiment illustrates the measurement of 

 the power-factor in both inductive and non-inductive portions 

 of a circuit. 



EXPERIMENT VIII. DETERMINATION OF THE POWER- 

 FACTOR OF A CIRCUIT. 



DIAGRAM OF CONNECTIONS. 



\AAAAAr 

 Ri- 



FIG. 27. 



R 

 R, 

 W 

 V 

 A 



vs 



source of alternating current. 



inductive portion of circuit in which power-factor 



is to be determined, 

 non-inductive portion, 

 resistance for varying current, 

 wattmeter for measuring power of circuit, 

 voltmeter for measuring voltage of circuit. 



ammeter for measuring current of circuit. 



2-way voltmeter switch. 



Instructions. Connect in series an inductive resistance, 

 a non-inductive resistance, and variable resistance. 



Put an ammeter in the circuit, and connect a voltmeter 

 across the portion in which the power-factor is to be 

 determined. 



Connect a wattmeter to read the same voltage and current 

 as the voltmeter and ammeter. In order to be able to measure 

 the power-factor in the non-inductive portion of the circuit 

 alone, connect the common lead from the voltmeter and 

 wattmeter shunt to a two-way switch, in such a way as to 

 be able to put the instruments across the non-inductive 

 part of the circuit or across both resistances at will, 



