I know carnot engine consists of isothermal and adiabatic process. My question is why the efficiency of carnot engine is maximum?
Why not it is maximum with other processes.
In one book I read that it is maximum because it is based on reversible cycle. I could not understand. Please help me out.
Best Answer
Lets look at some of the corollaries of the fact that the Carnot efficiency is $$\eta_{carnot}=1-\frac{T_H}{T_C}$$ where $T_H$ and $T_C$ are the fixed temperatures of the hot and cold reservoirs respectively (as these reservoirs are considered infinitely large).
Consider these $3$ cases:
So from these $3$ cases we conclude that no heat engine operating between two reservoirs can have a greater efficiency than a Carnot engine.