An ohmic resistor converts electrical energy into heat at a rate proportional to resistance and squared current.
Difficulty
Intermediate
Read time
5 min
Prerequisites
Basic algebra, consistent units, and the stated model assumptions
Source
OpenStax, College Physics 2e, §20.5 (Paul Peter Urone and Roger Hinrichs)OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example.
An ohmic resistor converts electrical energy into heat at a rate proportional to resistance and squared current. Current direction does not change the nonnegative power dissipated.
| Symbol | Meaning | Units |
|---|---|---|
| Power | ||
| Electric current | ||
| Electrical Resistance |
Estimate electrical dissipation from current.
Compare resistive heating as current changes.
A 5.00 Ω resistor carries a steady 2.00 A current. Find its dissipated power.
OpenFormulaGraph equation reference; FormuLab adaptation details and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted wording, notation, applicability conditions and topic placement, and expanded the numerical check into a worked example.
Assumptions
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