The eddy current loss in a dc generator is 400 W at 40 Hz frequency of reversal and constant flux density. When frequency is increased to 50 Hz., eddy current loss is :
(A) 256 W (B) 320 W (C) 500 W (D) 625 W
(A) 256 W (B) 320 W (C) 500 W (D) 625 W