ADVANCED BACK EMF PHYSICS QUESTION FOR DC MOTOR?
As the shaft in a DC motor is restricted from pivoting when a 6.0 V DC is administered, the current through the armature is 8.0 A. When the shaft can pivot, the current drops to 2.0 A. Calculate the Back EMF when the pole is pivoting.
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- Andrew SmithLv 71 year agoFavorite Answer
V/I = R
R = 6 / 8 = 0.75 Ohm
Now when spinning the net emf = I R = 2 * 0.75 = 1.5 V
1.5 = 6 - x -> x = 4.5 V
ie the back emf when spinning = 4.5 V and the remainder of the emf is used within the resistance of the motor.
- Anonymous1 year ago