Wiring and componentsQuestion 804 of 1506

What does "MCM" mean for a conductor size?

  1. Maximum current mark
  2. Thousands of circular mils
  3. Multi-core metal
  4. Metric cross-section measure
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Correct answer: Thousands of circular mils

The first M is the old Roman numeral for thousand.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 12.2: Conductor Size

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Questions last reviewed: 18 October 2026