Question

What is the formula for the radius at the centre of gravity?

(a) radius at the centre of gravity = inner diameter^1.5/6.3

(b) radius at the centre of gravity = inner diameter^2/6.3

(c) radius at the centre of gravity = outer diameter^1.5/6.3

(d) radius at the centre of gravity = outer diameter^2/6.3

The question was asked at a job interview.

This intriguing question originated from Frames of D.C. & A.C. Machines in division Aspects of Design of Mechanical Parts of Design of Electrical Machines

Answer 1

The correct choice is (c) radius at the centre of gravity = outer diameter^1.5/6.3

To elaborate: The outer diameter of stator core is first calculated. On substituting the values the radius at the centre of gravity is obtained.