450 



ELECTRICAL MEASUREMENTS 



be in time phase with I s , the current which flows in S. The 

 induced voltage, E s , must overcome the reactance drop due to 

 $ s and the ohmic drop in S. The fluxes < P and $ s differ in time 

 phase, being somewhat more than 90 apart, and will produce a 

 torque on the movable element. 



FIG. 260A. Electric and magnetic circuits of Westinghouse induction 



ammeter. 



/ is the line current and as the arrangement is a sort of current 

 transformer, 



<*>* = K 2 I 



KJ 



These values inserted in (1) give for the torque, 



PROPERTY OF ELECTRICAL L'.IORATORY, 



FACULTY OF APPLIED SCIENCE. 



