An electrician is preparing to check the insulation integrity of a de-energized motor winding. Which instrument and method is correct for this task, and what does a low or falling reading indicate?

1. A. A clamp-on ammeter measuring leakage current; a rising reading indicates good insulation
2. ✓ A megohmmeter applied conductor-to-ground; a low or falling reading warns of moisture, contamination, or insulation breakdownCorrect
3. C. A standard ohmmeter applied across the winding terminals; a reading near zero indicates a healthy winding
4. D. A voltmeter applied phase-to-ground with the circuit energized; a reading below rated voltage indicates insulation failure