Question

How is the value of the magnetic to electrical boarding ratio related with the volume of iron and volume of copper?

(a) high magnetic to electrical boarding ratio gives high copper volume and high iron volume

(b) high magnetic to electrical boarding ratio gives low copper volume and high iron volume

(c) low magnetic to electrical boarding ratio gives low copper volume and low iron volume

(d) low magnetic to electrical boarding ratio gives low copper volume and high iron volume

This question was addressed to me in an online quiz.

My question is based upon Design Preliminaries topic in portion Design of Permanent Magnet (PM) DC Motors of Design of Electrical Machines

Answer 1

Correct choice is (b) high magnetic to electrical boarding ratio gives low copper volume and high iron volume

To elaborate: The high value of magnetic to electrical boarding ratio gives a high volume of iron. But the high value of magnetic to electrical boarding ratio gives low copper volume.