For the expansion occuring from initial to final stage in finite time, which is incorrect?

Options

A. Equilibrium exist in initial and final stage
B. Work obtained is maximum
C. Driving force is much greater than the opposing force
D. Both (1) & (2)

Answer

To solve the question regarding the incorrect statement for the expansion occurring from an initial to a final stage in finite time, we will analyze the concepts of thermodynamics involved in irreversible processes and equilibrium states.

### Step-by-Step Solution:

1. **Understanding the System**:
- We have a gas in a container that is initially at equilibrium, meaning the pressure inside the container is equal to the external pressure.

**Hint**: Remember that equilibrium means no net force acting on the system.

2. **Changing Conditions**:
- When we change the conditions (e.g., by reducing the external pressure), the gas will expand. This change occurs in finite time, meaning it is not a slow, gradual process.

**Hint**: Consider how quick changes in pressure affect the behavior of gases.

3. **Irreversible Process**:
- The process of expansion in this scenario is irreversible because it happens quickly and does not allow the system to adjust gradually to the new conditions.

**Hint**: Recall that irreversible processes do not return to their original state without external work.

4. **Equilibrium States**:
- At the initial and final states, the system is at equilibrium. However, during the expansion, there is no equilibrium in the intermediate state because the gas is rapidly moving to a new volume.

**Hint**: Identify when the system is in equilibrium and when it is not.

5. **Work Done**:
- The work done during this expansion is not maximum because it is an irreversible process. Maximum work is associated with reversible processes where the system can adjust gradually.

**Hint**: Think about the relationship between work and the nature of the process (reversible vs. irreversible).

6. **Conclusion**:
- The incorrect statement regarding the expansion is that "equilibrium exists in the intermediate stage." This is false because the system does not reach equilibrium until the final state is achieved.

**Hint**: Focus on the definition of equilibrium and how it applies to different stages of a process.

### Final Answer:
The incorrect statement is: "Equilibrium exists in the intermediate stage."