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A motor operating on 100 V draws a current of 1 A. If the efficiency of the motor is 91.6\%, then the loss of power in units of cal/s is
(2) 2
Input power: Pin = VI = 100 1 = 100 W
Useful (output) power: Pout = 91.6\% of 100 W = 91.6 W
Power lost = 100 - 91.6 = 8.4 W = 8.4 J/s
1 cal = 4.2 J
Power lost = 8.44.2 = 2 cal/s
Answer: (2)
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