I really need help in calculating the magnetic field generated by a horse-shoe shaped solenoid which is being used as a permanent magnet in a DC motor. The calculation is VITAL (well, I think so) as I need it to be able to predict the angular speed (in revs per minute) of my motor. If there is sa way to do the prediction without this, I would gratly appreciate it. FYI - We are being source a 10 volt, 2 amp current to make the motor spin. I need help ASAP as if my motor doesn't work, I fail this subject at University.