An adiabatic reversible process is one in which?

Options

A. Temperature of the system is not change
B. The system is not closed to heat transfer
C. There is no change in entropy
D. There is no net work done

Answer

To answer the question "An adiabatic reversible process is one in which?", we need to understand the definitions and implications of both adiabatic and reversible processes in thermodynamics.

### Step-by-Step Solution:

1. **Definition of Adiabatic Process**:
- An adiabatic process is defined as one in which there is no heat transfer into or out of the system. This means that the heat exchange (Q) is equal to zero (Q = 0).

2. **Implications of Adiabatic Process**:
- Since there is no heat transfer, any change in the internal energy of the system must be due to work done on or by the system. This can be expressed using the first law of thermodynamics:
\[ \Delta U = Q + W \]
In an adiabatic process, this simplifies to:
\[ \Delta U = W \]

3. **Definition of Reversible Process**:
- A reversible process is one that can be reversed without leaving any change in the system and the surroundings. It occurs infinitely slowly, allowing the system to remain in equilibrium at all stages.

4. **Isentropic Process**:
- An adiabatic reversible process is also known as an isentropic process. In this type of process, there is no change in entropy (ΔS = 0). This is because, with no heat transfer, the entropy of the system remains constant.

5. **Evaluating Statements**:
- Now, let’s evaluate the options given in the question:
- **Option 1**: The temperature of the system doesn't change. (Incorrect, as temperature can change in an adiabatic process.)
- **Option 2**: The system is not closed to heat transfer. (Incorrect, as it is defined to have no heat transfer.)
- **Option 3**: There is no change in entropy. (Correct, as it is an isentropic process.)
- **Option 4**: There is no net work done. (Incorrect, as work can be done in an adiabatic process.)

6. **Conclusion**:
- The correct statement regarding an adiabatic reversible process is that there is no change in entropy.

### Final Answer:
An adiabatic reversible process is one in which there is no change in entropy.