Realise that Carnot Cycle is not a practical possibility.
It is shown that the efficiency of a Carnot cycle is the highest achievable, but that its power output is zero.

Heat Engines: the Carnot Cycle. Michael Fowler . Applet here! Equation 12-2 provides the thermal efficiency of the Carnot cycle where the temperatures are in degrees Kelvin, the absolute temperature scale. 1st part-Since from the carnot cycle and 2nd law of thermodynamics, we know that efficiency for any cyclic process is maximum when it is a reversible carnot cycle .Since efficiency is maximum ,the work done is also maximum for reversible process So it’s easy to see how to turn heat into work, but that’s a one shot deal. All standard heat engines (steam, gasoline, diesel) work by supplying heat to a gas, the gas then expands in a cylinder and pushes a piston to do its work. The sequence of steps—isothermal expansion, adiabatic expansion, isothermal compression, adiabatic compression—are processes that can be done reversibly or irreversibly. Compound engines (engines with more than one stage of expansion) had already been invented, and there was even a crude form of internal-combustion engine, with which Carnot was familiar and which he described in some detail in his book. A reversible isothermal gas expansion process. The reversible Carnot cycle is compared to a range of engine cycles. Although there existed some intuitive understanding of the workings of engines, scientific theory for their operation was almost nonexistent. The only difference is that here more than two heat reservoirs are involved. In fact, a Carnot engine is the only possible engine which can operate between just two temperatures; all other engines require one or more heat source or heat sink at some intermediate temperatures.

A Carnot engine operating between temperature `T_1 and T_2` has efficiency 1/6. When `T_2` is lowered by 62K its efficiency increase to 1/3.

1. The Ultimate in Fuel Efficiency for a Heat Engine. Learn the concepts of Class 11 Physics Thermodynamics with Videos and Stories.

Carnot cycle is an ideal cycle that was developed by Leonard Sadi Carnot. In this section, we will learn about the Carnot cycle and Carnot Theorem in detail. It gives the estimate of the maximum possible efficiency that a heat engine during the conversion process of heat into work and conversely, working between two reservoirs, can possess.


This seems to be as reversible an engine as the Carnot engine. Define what is carnot engine, explain carnot cycle, establish carnot theorem, prove carnot cycle is universal. The Carnot cycle is a reversible heat engine operating from hot and cold reservoirs at constant temperatures of T H and T L, respectively. It mainly consists of four reversible processes. Novikov engine showing irreversible heat transfer between T_H and T_iH, coupled to a Carnot cycle operating between T_iH and T_C. Carnot engine is a theoretical thermodynamic cycle proposed by Leonard Carnot.