Question 213Electricity & Electronics - Assistant Engineer

The correct answer is D) open field coil. An ohmmeter reading of infinity indicates that the circuit is open, meaning there is no continuity and the coil is not completing the circuit. This would suggest that the field coil in the AC motor stator is open, which could be caused by a break or fault in the winding. The other options are incorrect because a grounded field coil (A) would show a low resistance reading, a shunted field coil (B) would show a lower than expected resistance, and a shorted field coil (C) would show a very low or near-zero resistance reading, not an open circuit indicated by an infinity reading.