DC circuitsQuestion 1337 of 1506

A 40 Ω resistor is connected across a 120 V supply. How much power does it dissipate?

  1. 4800 W
  2. 360 W
  3. 6.00 W
  4. 180 W
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Correct answer: 360 W

P = V² ÷ R = (120 V)² ÷ 40 Ω = 360 W.

Source: Computed, 2.4: Calculating Electric Power

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Questions last reviewed: 18 October 2026