Question

A Carnot cycle consists of the following steps

• A. Two isobaric and two isothermal
• B. Two isochoric and two isobaric
• C. Two isothermal and two isochoric
• D. Two isothermal and two isentropic

Hint:

Carnot cycle has two isothermal processes and two reversible adiabatic or isentropic processes.

Answer 1

The Correct Option is D

A Carnot cycle is an ideal reversible cycle. It consists of four reversible processes. The first process is isothermal expansion at high temperature: \[ T_H=\text{constant} \] The second process is reversible adiabatic expansion. For a reversible adiabatic process: \[ S=\text{constant} \] So it is also called an isentropic process. The third process is isothermal compression at low temperature: \[ T_L=\text{constant} \] The fourth process is reversible adiabatic compression, which is again isentropic. Therefore, the Carnot cycle contains: \[ 2\text{ isothermal processes} \] and \[ 2\text{ isentropic processes} \] Hence, the correct answer is: \[ \text{Two isothermal and two isentropic} \]