Hello there, I have this simple question on generator theory which is bogging me down. I know that the resistance of the field windings of a shunt generators should be less than a certain critical resistance otherwise the emf produced by the residual magnetism will not be sufficient to develop any voltage in the generator. Is there any minimum limit to the resistance also? Is there any such limiting value of field resistance below which the resistance should not decrease? If so, then what will happen if the resistance of the field decreases below this minimum value. Thank you in advance for responding.