Power factor and three-phaseQuestion 495 of 1506

In a purely resistive circuit, what form does the true power take?

  1. Heat or light, measured in watts
  2. Stored magnetic energy, measured in vars
  3. Apparent power, measured in volt-amperes
  4. Quadrature power, measured in vars
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Correct answer: Heat or light, measured in watts

Resistance dissipates power as heat or light.

Source: Trigonometry and Single Phase AC Generation for Electricians (Flinn), 1.6: Power and Impedance Triangles

Practice power factor and three-phase

Questions last reviewed: 18 October 2026