Question

What is the range of the ratio of the pole length to pole pitch?

(a) 0.60-0.70

(b) 0.64-0.72

(c) 0.65-0.75

(d) 0.70-0.80

This question was addressed to me in an internship interview.

This interesting question is from Separation of D and L, Standard Frames topic in chapter General Concepts and Constraints in Design of Rotating Machines of Design of Electrical Machines

Answer 1

The correct option is (b) 0.64-0.72

The best explanation: The minimum value of the ratio of the pole length to pole pitch is 0.64. The maximum value of the ratio of the pole length to pole pitch is 0.72.