Question

To determine the efficiency of the machine, direct load test is not advantageous because of which of the following reasons?

(a) Cost of providing large inputs

(b) Difficulty of dissipating the large outputs

(c) Both cost of providing large inputs and difficulty in dissipating the large outputs

(d) None of the mentioned

I have been asked this question in an internship interview.

This intriguing question comes from Losses and Efficiency in section Rating and Loss Dissipation of Electrical Machines

Answer 1

Right choice is (c) Both cost of providing large inputs and difficulty in dissipating the large outputs

The explanation is: Also, a small error in the measurement of either output or input causes the same amount of error in the computed efficiency.