Question

What is the formula for the thickness of the ac machines?

(a) thickness = 40 * inner diameter of frame/12

(b) thickness = 40 + inner diameter of frame/12

(c) thickness = 40 – inner diameter of frame/12

(d) thickness = 40 * inner diameter of frame*12

This question was posed to me in final exam.

I'd like to ask this question from Frames of D.C. & A.C. Machines in chapter Aspects of Design of Mechanical Parts of Design of Electrical Machines

Answer 1

The correct answer is (a) thickness = 40 * inner diameter of frame/12

To elaborate: The thickness of the ac machines depend upon the inner diameter of the frame. On obtaining the inner diameter of frame and on substitution gives the thickness of ac machines.