Question

An isenthalpic process is a process during which __________ remains constant.
1. temperature
2. entropy
3. enthalpy
4. pressure

Answer 1

Correct Answer - Option 3 : enthalpy

Explanation:

Isenthalpic process

• A thermodynamic process in which enthalpy of a system remains constant is known as Isenthalpic process.
• Throttling process is one of the example of Isenthalpic process.
• Throttling (Isenthalpic) process:
  • A throttling process occurs when a fluid flowing through a passage suddenly encounters a restriction in the passage.
  • The restriction could be due to the presence of an almost completely closed valve or due to sudden and large reduction in flow area etc.
  • The result of this restriction is a sudden drop in the pressure of the fluid as it is forced to flow through the restriction. This is a highly irreversible process and is used to reduce the pressure and temperature of the refrigerant in a refrigeration system.

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Other important processes are:

• Isothermal process: When a thermodynamic system undergoes a physical change in such a way that its temperature remains constant, then the change is known as an isothermal process.
• Isobaric process: When a thermodynamic system undergoes a physical change in such a way that its pressure remains constant, then the change is known as the isobaric process.
• Isochoric process: When a thermodynamic process undergoes a physical change in such a way that its volume remains constant, then the change is known as the isochoric process.
• Adiabatic process: When a thermodynamic system undergoes a change in such a way that no exchange of heat takes place between Systems and surroundings, the process is known as an adiabatic process.
• Isentropic Process: An isentropic process is also known as a reversible adiabatic process. As this is an adiabatic process so no heat enters or leaves the system.
• \(dS = \frac{{d{Q_{rev}}}}{T}\)
• If the process is reversible and adiabatic: dQrev = 0 ⇒ dS = 0
• In an isentropic process, entropy remains constant.