Question

What should be the range of the product of the magnetic field and magnetic flux density?

(a) 4-4.5 * 10^6

(b) 4-4.3 * 10^6

(c) 4.3-4.6 * 10^6

(d) 4.2-4.5 * 10^6

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

I'd like to ask this question from Design Steps and Considerations in chapter Design of Permanent Magnet (PM) DC Motors of Design of Electrical Machines

Answer 1

Right choice is (c) 4.3-4.6 * 10^6

The best I can explain: The product of the magnetic field and magnetic flux density has a minimum value of 4.3 * 10^6. The product of the magnetic field and magnetic flux density has a minimum value of 4.6 * 10^6.