Question

What is the relationship between efficiency and the operating costs?

(a) efficiency is directly proportional to the square of the operating cost

(b) efficiency is directly proportional to the operating costs

(c) efficiency is indirectly proportional to the operating costs

(d) efficiency is indirectly proportional to the square of the operating costs

I had been asked this question during an internship interview.

This question is from Design of Machines, Limitations in Design topic in chapter Fundamental Aspects of Electrical Machine Design of Design of Electrical Machines

Answer 1

Right choice is (c) efficiency is indirectly proportional to the operating costs

Explanation: Efficiency is one of the limitations in the design of the machines. The efficiency should be as high as possible to reduce the initial cost.