【Daily Question】Theoretical Foundation 2020.05.19
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Multiple-choice question: If the area enclosed by the cycle curve of a Carnot cycle increases from abcda in the diagram to ab’c’da, then what happens to the net work produced by the cycles abcda and ab’c’da, as well as to the efficiency of the heat engine? ( ) (A) The net work increases, and the efficiency improves. (B) The net work increases, and the efficiency decreases. (C) Both net work and efficiency remain unchanged. (D) The net work increases while the efficiency remains unchanged. Answer: D. Hint: Extra rewards will be given to those who can explain the solution process; the answer can be found there!
D. The Carnot cycle is the most efficient ideal cyclic process, using an ideal gas as the working substance and consisting of two isothermal processes and two adiabatic processes. The net work done by the system is numerically equal to the area enclosed by the closed loop curve. Also, η_Carnot = 1 – T2/T1