Heat transfer in a Carnot cycle takes place at_______________________?
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Answer: C. constant temperature
Explanation
The Carnot cycle consists of two isothermal and two reversible adiabatic processes occurring sequentially. Heat addition and heat rejection take place exclusively during the isothermal expansion and compression stages. Isothermal processes occur at constant temperature using thermal reservoirs maintained at fixed temperature levels. Sadi Carnot introduced this theoretical thermodynamic cycle in eighteen twenty four to analyze engine limits. Thermal reservoirs supply or absorb heat without experiencing any temperature changes during the heat transfer. Constant temperature heat transfer ensures maximum reversibility and eliminates internal thermal gradients entirely.
Power plant engineers use the Carnot efficiency standard to measure the imperfection of real power cycles. Refrigeration systems also analyze reversed Carnot cycles to establish theoretical performance benchmarks. Maintaining constant source and sink temperatures is essential for theoretical thermodynamic cycle analysis. Option A is incorrect because constant pressure heat transfer occurs in Brayton and Rankine cycles. Option B describes constant volume heat addition typical of ideal Otto cycle internal combustion engines. Option D is invalid because enthalpy changes do not define the primary heat addition mechanism here.
- Subject
- Engineering
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- Mechanical Engineering
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- —
- Difficulty
- medium
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