Electrical mathQuestion 831 of 1506

You use a specific resistance in ohm-centimetres in R = ρl/A. In which units must length and area be?

  1. Length in metres and area in square metres
  2. Length in cm and area in square cm
  3. Length in millimetres and area in circular mils
  4. Length in centimetres and area in square metres
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Correct answer: Length in cm and area in square cm

The units of the length and area must match the length unit inside the specific resistance.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 12.5: Specific Resistance

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Questions last reviewed: 18 October 2026