Red Seal Electrician Practice
DC circuitsQuestion 1385 of 1506

A copper conductor measures 20 Ω at 20 °C. What is its resistance at 60 °C? Use 0.004041 per °C for copper.

  1. 16.8 Ω
  2. 23.2 Ω
  3. 24.8 Ω
  4. 3.23 Ω
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Correct answer: 23.2 Ω

R = R20 × (1 + α × ΔT) = 20 × (1 + 0.004041 × 40) = 23.2 Ω.

Source: Computed, 12.6: Temperature Coefficient of Resistance

Practice dc circuits

Questions last reviewed: 18 October 2026