Question 13012 of 731 · Texas Journeyman Electrician Exam
A motor delivers 10 horsepower at the shaft while drawing 8.5 kW of electrical input. What is its efficiency?
Exactly one answer is correct.
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Correct answer to question 13012
- D: 87.8 %
Explanation
Output is 10 x 746 W = 7,460 W, so efficiency = output / input = 7,460 / 8,500 = 87.8 %. Dividing input by output gives a value above 100 %, which is impossible for a motor.
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