gen-state-the-carnot-cycle-precisely-and-explain-why-it-matters-05ab

State the Carnot cycle precisely and explain why it matters in 2-3 sentences.

## The Carnot Cycle A reversible thermodynamic cycle consisting of four steps: (1) isothermal expansion at hot temperature T_H, (2) adiabatic expansion, (3) isothermal compression at cold temperature T_C, and (4) adiabatic compression, returning to the initial state. ## Why It Matters The Carnot cycle establishes the theoretical maximum efficiency (η = 1 - T_C/T_H) that any heat engine can achieve operating between two temperatures, proving that this limit depends only on the temperature reservoirs, not the working substance. This fundamental result shows that perfect conversion of heat to work is impossible (contributing to the second law of thermodynamics) and provides the benchmark against which all real engines are measured.