116 EFFECT OF CAPACITY. 



These are the general expressions for the impedance 

 and angle of lag in an alternating circuit. If the circuit 

 is non-inductive L becomes zero. 



The following experiment serves to illustrate what 

 has just been said. 



EXPERIMENT XXI. DETERMINATION OF POWER AND 

 PHASE KELATIONS IN A CIRCUIT CONTAINING RESISTANCE, 

 SELF-INDUCTION, AND CAPACITY. 



DIAGRAM OF CONNECTIONS. 



FIG. 55. 



M l M 2 Source of alternating current. 

 R Non-inductive resistance. 

 r Inductive resistance. 

 C Condenser. 



A Ammeter for measuring current in circuit. 

 V* Voltmeter for measuring respectively voltage 

 of inductive and non-inductive resistance, 

 condenser, and total circuit. 

 S Switch for breaking circuit. 



Instructions. Connect in series to the source of supply 

 a non-inductive resistance, inductive resistance, condenser, 

 and ammeter. Connect a voltmeter to read in turn the 

 total voltage of the circuit, and the voltage across each 

 resistance an.d the condenser, and across the inductive and 

 non-inductive resistances together. It is an advantage 

 to insert a wattmeter in the circuit to serve as a check on 

 the accuracy of the other readings. 



For several values of the non-inductive resistance and 

 current, take readings of the current and voltage of induc- 

 tive and non-inductive resistances, and also the resultant 



\ 



voltage across both resistances. Read also the voltage at 



* Only a single voltmeter is actually necessary, and should be connected 

 successively to the different terminals indicated in the diagram. 



