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Engineering Sciences
Electrical Engineering
1840
Beginner

Electrical Power Equation

P=IV=I2RP = IV = I^2 R

Electrical power equals current times voltage, or current squared times resistance.

By James Prescott Joule, Various

Engineering Sciences
Electrical Power Equation
1840 · James Prescott Joule
Why it matters: Foundation of power grids, electronics, and energy management.

Discoverers: James Prescott Joule, Various (1840)

What does it mean?

Electrical power equals current times voltage, or current squared times resistance.

Why should I care?

Foundation of power grids, electronics, and energy management.

Variables & Units

SymbolNameUnitMeaning
PPPowerWElectrical power
IICurrent—Amperes
VVVoltage—Volts
RRResistance—Ohms

Worked Example

120V, 10A appliance draws P = 1200 W.

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Sources & further reading

Search WikipediaSearch Wolfram MathWorldOpen in Wolfram|AlphaWatch explainers on YouTube

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Electrical Power Equation

P=IV=I2RP = IV = I^2 R

Real-world impact

Wireless technology

Electromagnetic waves carry information worldwide.

Photo: Unsplash — network infrastructure

Electrical power equals current times voltage, or current squared times resistance.

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