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Question
Answer in brief.
Why should a Carnot cycle have two isothermal two adiabatic processes?
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Solution
There are basically two processes:
- Exchange of heat (steps A to B and C to D). For this to be reversible, the heat exchange must be isothermal. This is possible if the working substance is at the temperature TH of the source while absorbing heat. The working substance should be at the temperature of the cold reservoir TC while rejecting the heat.
- Work done (steps B to C and D to A). For work done to be reversible, the process should be adiabatic.
Thus, the cycle includes two isothermal and two adiabatic processes for maximum efficiency.
Carnot cycle
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