In case of compression, isothermal curve lies…..the adiabatic curve. Fill in the blanks

Options

A. above
B. below
C. sometimes above and other time below
D. cannot say

Explanation

To determine the relationship between isothermal and adiabatic curves during compression, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concepts**:
- **Isothermal Process**: A process that occurs at a constant temperature. For an ideal gas, the isothermal curve on a Pressure-Volume (P-V) graph is hyperbolic.
- **Adiabatic Process**: A process that occurs without heat transfer. The adiabatic curve is steeper than the isothermal curve for the same initial and final states.

2. **Draw the P-V Graph**:
- On a graph, label the x-axis as Volume (V) and the y-axis as Pressure (P).
- Draw a hyperbolic curve representing the isothermal process.
- Draw a steeper curve representing the adiabatic process.

3. **Identify the Compression Direction**:
- In a compression process, the volume decreases. This means we are moving leftward along the x-axis (from higher volume to lower volume).

4. **Locate the Curves**:
- Identify a common point on both curves. As we move left (compressing the gas), we need to observe the relative positions of the isothermal and adiabatic curves.
- The adiabatic curve will always lie above the isothermal curve during compression.

5. **Conclusion**:
- Therefore, in the case of compression, the isothermal curve lies **below** the adiabatic curve.

### Final Answer:
In case of compression, the isothermal curve lies **below** the adiabatic curve.

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