Meters and troubleshootingQuestion 582 of 1506

Insulation on a high-voltage cable may be weakened by past breakdown. Which instrument finds this kind of failure?

  1. A standard clamp meter set to read current in the cable
  2. A low-voltage ohmmeter with a 9 V battery inside
  3. A high-voltage resistance meter, 1000 V or more
  4. A continuity buzzer set to its most sensitive range
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Correct answer: A high-voltage resistance meter, 1000 V or more

Damaged insulation may still look sound at low voltage, so a high-voltage resistance meter is used to detect it.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 2.6: Nonlinear Conduction

Practice meters and troubleshooting

Questions last reviewed: 18 October 2026