Electrical mathQuestion 829 of 1506

A copper conductor has a resistance of 4 Ω. A new piece of the same copper has 3 times the length and 3 times the cross-sectional area. What is its resistance?

  1. 12 Ω
  2. 36 Ω
  3. 1.33 Ω
  4. 4 Ω
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Correct answer: 4 Ω

Resistance is proportional to length and inversely proportional to area. The factor 3 cancels, so R stays 4 Ω.

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

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Questions last reviewed: 18 October 2026