Red Seal Electrician Practice
DC circuitsQuestion 571 of 1506

The voltage across a fixed resistance is doubled. What happens to the power?

  1. It doubles
  2. It stays the same
  3. It is cut in half
  4. It becomes four times larger
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Correct answer: It becomes four times larger

Both voltage and current double, so power rises by 2 x 2 = 4.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 2.4: Calculating Electric Power

Practice dc circuits

Questions last reviewed: 18 October 2026