In a dc machine dull yellow spark indicates HomeDC Motor MCQsIn a dc machine dull yellow spark indicatesQ. In a dc machine dull yellow spark indicatesA. Winding faultB. Excessive brush wearC. Excessive noiseD. None of theseAnswer: None of these
A shunt motor is fitted with a field regulator for speed control. For constant torque load, the speed will be minimum when the resistance of the regulator is