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Physical Sciences
Thermodynamics
1824
Intermediate

Carnot Efficiency

η=1TCTH\eta = 1 - \frac{T_C}{T_H}

Maximum efficiency of any heat engine operating between hot and cold reservoirs.

By Sadi Carnot

Physical Sciences
Carnot Efficiency
1824 · Sadi Carnot
Human Reviewed
84%

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Why it matters: Guided power plant design and proved the impossibility of perpetual motion.

Discoverers: Sadi Carnot (1824)

What does it mean?

Maximum efficiency of any heat engine operating between hot and cold reservoirs.

Why should I care?

Guided power plant design and proved the impossibility of perpetual motion.

Equation Compass

North — Prerequisites

West — History

South — Derivations

Variables & Units

SymbolNameUnitMeaning
ηηEfficiencyThermal efficiency
THT_HHot reservoirKHigh temperature
TCT_CCold reservoirKLow temperature

Worked Example

T_H=600K, T_C=300K → η_max = 50%.

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Equation Universe

Carnot Efficiency

η=1TCTH\eta = 1 - \frac{T_C}{T_H}

Real-world impact

Energy infrastructure

Thermodynamic limits shape power and transport.

Photo: Unsplash — power plant

Maximum efficiency of any heat engine operating between hot and cold reservoirs.

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