Electrical mathQuestion 1368 of 1506

A 1.5 kW heater runs 3 hours each day for 30 days. How much energy does it use?

  1. 45.0 kWh
  2. 67.5 kWh
  3. 4.50 kWh
  4. 135 kWh
Show answer

Correct answer: 135 kWh

Energy = power × time = 1.5 kW × 3 h × 30 days = 135 kWh.

Source: Computed, 12.3: Power Measurement

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Questions last reviewed: 18 October 2026