Isentropic Process

An isentropic process is a thermodynamic process in which the entropy remains constant. It is a reversible and adiabatic process, which means that no heat is exchanged with the surroundings, and there is no friction or other dissipative forces.

Frictionless and Adiabatic

The correct answer to the given question is option 'C,' i.e., frictionless and adiabatic. This is because an isentropic process is always adiabatic, and there is no heat exchange with the surroundings. Moreover, it is also frictionless because there is no dissipative force acting on the system.

Reversible and Isothermal

Option 'A' is incorrect because an isentropic process is not always isothermal, which means that there is no constant temperature throughout the process. Moreover, it is not reversible because it involves a change in the entropy of the system.

Irreversible and Adiabatic

Option 'B' is also incorrect because an isentropic process is always reversible, and it does not involve any dissipative forces. Therefore, it cannot be irreversible.

Frictionless and Isothermal

Option 'D' is also incorrect because an isentropic process is not always isothermal, and it cannot be both adiabatic and isothermal at the same time. Therefore, it cannot be frictionless and isothermal.

Conclusion

In conclusion, an isentropic process is always frictionless and adiabatic, which means that there is no dissipative force acting on the system, and there is no heat exchange with the surroundings. This process is essential in many engineering applications, including gas turbines, compressors, and steam power plants.