I NEED HELP in MAGNETIC CIRCUITS

1. Oct 7, 2005

rockerboi

I'm not sure if my answer is correct, I need someone to help me solve this so I could check my answer..

1.) 2 coils A and B are magnetically coupled. When connected in parallel-aiding, the total inductance is 2.33 H, and when connected in parallel-opposing the total inductance is 1.4H. The mutual inductance is 1H. What will happen to the coefficient of coupling if the 2 coils were connected in a series assuming that the mutual inductance remains the same?

2.) The flux density in the 0.2" air gap of an electric motor is 42,000 maxwells per sq. in. If the mmf required to produce this flux is 82% of the total mmf developed by the exciting coil, calculate the number of turns in the winding,assuming a current of 2.2 A.

Thanks guys!!!

2. Oct 7, 2005

mezarashi

As per usual protocol, I guess it would be proper for you to post your own attempts or solutions >_>. Not my rules, but I see good reason for them.

3. Oct 8, 2005

Gokul43201

Staff Emeritus
rocker, if you're not aware of the guidelines regarding schoolwork, please click my signature line.

4. Oct 9, 2005

rockerboi

ok! i'll send my solution next time coz i'm in a hurry..i've got so many exams