"Power is the rate at which energy of any type is transferred; **electric power** is the rate at which electric energy is transferred in a circuit."
"But a Coulomb per second (C/s) is an electric current, which we can see from the definition of electric current... Thus, the equation above tells us that electric power is voltage times current, or P = IV."
"Thus, by combining Ohm's law with the equation P = IV for electric power, we obtain two more expressions for power: one in terms of voltage and resistance and one in terms of current and resistance."
"This means that the physical characteristic of a circuit that determines how much power it dissipates is its resistance."
Show moreShow less
"Power is the rate at which energy of any type is transferred; electric power is the rate at which electric energy is transferred in a circuit."
"But a Coulomb per second (C/s) is an electric current, which we can see from the definition of electric current... Thus, the equation above tells us that electric power is voltage times current, or P = IV."
"Thus, by combining Ohm's law with the equation P = IV for electric power, we obtain two more expressions for power: one in terms of voltage and resistance and one in terms of current and resistance."
"This means that the physical characteristic of a circuit that determines how much power it dissipates is its resistance."
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