74 



great, the anomalous result follows, that 

 the output of the large transformer is 

 zero, although its electromotive force 

 would be four times that of the other. 

 The comparison would have been still 

 more unfavorable to the large trans- 

 former, had it been assumed that the 

 iron heat in the small transformer was 

 greater than its copper heat. Therefore 

 in order to be able to work the large 

 transformer at all, the induction must be 

 reduced ; that is to say, the transformer 

 used on a circuit, the electromotive force 

 of which is less than four times that of 

 the small transformer. The resistance 

 of the large coil is half that of the small 

 one, and if the large transformer is 

 worked so as to have equal iron and 

 copper heat, the latter may obviously be 

 four times that of the small transformer ; 

 this gives a current 2.82 times the value 

 of that in the small transformer. The 

 weight of iron in the large transformer 

 being eight times that of the small one, 

 the loss by hysteresis per unit of weight 

 must be half. The corresponding indue- 



