19.4
"Electric power P is defined as the rate at which electrical energy is transferred by an electric circuit: P = IV. The SI unit of power is the watt (W)."
"The energy delivered to a circuit element is E = Pt. In terms of the kilowatt-hour (kWh), 1 kWh = 3.6 × 10⁶ J."
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"Electric power P is defined as the rate at which electrical energy is transferred by an electric circuit: P = IV. The SI unit of power is the watt (W)."
"The energy delivered to a circuit element is E = Pt. In terms of the kilowatt-hour (kWh), 1 kWh = 3.6 × 10⁶ J."
What you'll learn
- Define electric power and calculate it using P = IV
- Derive and apply the alternative forms P = I²R and P = V²/R
- Calculate electrical energy consumption and cost using E = Pt
- Explain why power transmission lines use high voltage and low current
- Interpret power ratings on household devices and calculate operating costs
Prerequisites
Slides
Interactive presentations perfect for visual learners • Interactive presentation
Slide Video
Watch narrated slides play like a video lesson • Narrated slide playback
Task-sets
Learning resource • 1 task-sets