EFFECT OF CAPACITY. 



113 



voltage. The power can, however, be obtained by the 

 use of a wattmeter, or by either of the methods given in 

 Experiments XIII. and XIV. for inductive circuits. The 

 diagrams of connections there given apply to the present 

 case also, with the substitution of the capacity for the 

 inductance. A special form of experiment is consequently 

 not necessary. 



The following record of an actual experiment 

 will serve as a guide as to the observations to be taken. 

 The readings practically form a companion experiment to 

 the 3-voltmeter method given as Experiment XIII. 



As in that case, the total power in the circuit is given 

 by the formula 



W V* + V 2 2 - V? 



2R 



while the power in the portion exclusive of the non- 

 inductive resistance is 



When V 3 = total voltage of circuit. 



V 2 = voltage of non-inductive portion. 



V l = voltage across portion including capacity. 



R = value of non-inductive resistance. 



Example of Determination of Power in Circuit containing 

 capacity. The actual connections made are shown in the 

 diagram Fig. 53, which is identical in principle with that 

 shown in Fig. 37, page 78, but shows the modification, 

 already frequently alluded to, of employing a single 

 voltmeter with two-way switches. It is to be noted that 



PIG. 53. DIAGRAM OF CONNECTIONS FOR DETERMINATION- OF POWER 

 IN CIRCUIT WITH CAPACITY. 



