Electrical power is the rate of electrical energy transfer at a circuit element.
Difficulty
Beginner
Read time
5 min
Prerequisites
Basic algebra and consistent SI units
Source
OpenStax, College Physics 2e, §20.4 (Paul Peter Urone and Roger Hinrichs)Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
Electrical power is the rate of electrical energy transfer at a circuit element. With the passive sign convention, positive power means the element absorbs energy and negative power means it supplies energy.
| Symbol | Meaning | Units |
|---|---|---|
| Signed electrical power | ||
| Current entering the positive terminal | ||
| Voltage across the element |
Estimate the rate of electrical energy consumption.
Distinguish supplied and absorbed power.
A DC device has 5.00 V across its terminals and draws 2.00 A into its positive terminal. Find the power it absorbs.
Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
Assumptions
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