Question

What is the range of the copper factor in PMDC motors?

(a) 0.1-0.3

(b) 0.1-0.2

(c) 0.1-0.4

(d) 0.2-0.4

This question was posed to me by my college professor while I was bunking the class.

This intriguing question comes from Design Preliminaries topic in division Design of Permanent Magnet (PM) DC Motors of Design of Electrical Machines

Answer 1

The correct choice is (b) 0.1-0.2

The explanation is: The copper factor represents the fraction of the armature circular area for conductors. The range of the copper factor is between 0.1-0.2.