A Carnot cycle operates a follows:-
1) It receives thermal energy isothermally from some hot reservoir maintained at a constant high temperature TH.
2) It rejects thermal energy isothermally to a constant low–temperature reservoir (T2).
3) The change in temperature is reversible adiabatic process.
Such a cycle, which consist of two isothermal processes bounded by two adiabatic processes, is called Carnot cycle.
