`{:(,"List-I",,"List-II"),(P,"Veloicty of sound",1.,"Minimum amplitude"),(Q,"Nodes",2.,"Maximum amplitude"),(R,"Antinodes",3.,"Independent of pressure"),(S,"Echo",4.,"Reflection of sound waves"):}`

Options

A. `{:(P,Q,R,S),(4,3,1,2):}`
B. `{:(P,Q,R,S),(3,1,2,4):}`
C. `{:(P,Q,R,S),(2,1,3,4):}`
D. `{:(P,Q,R,S),(1,3,4,2):}`

Answer

To solve the matching question between List-I and List-II, we will analyze each item in List-I and find the corresponding match in List-II.

### Step-by-Step Solution:

1. **Identify the first item in List-I (P: Velocity of sound)**:
- The velocity of sound is given by the formula \( V = \sqrt{\frac{\gamma P}{\rho}} \).
- Although it appears to depend on pressure (P) and density (ρ), it is important to note that when pressure increases, density also increases proportionally in gases, keeping the ratio \( \frac{P}{\rho} \) constant.
- Therefore, the velocity of sound is independent of pressure.
- **Match**: P → 3 (Independent of pressure).

2. **Identify the second item in List-I (Q: Nodes)**:
- Nodes are points in a standing wave where the amplitude is always zero.
- This means that at nodes, there is no displacement of the medium.
- **Match**: Q → 1 (Minimum amplitude).

3. **Identify the third item in List-I (R: Antinodes)**:
- Antinodes are points in a standing wave where the amplitude is at its maximum.
- This means that at antinodes, the displacement of the medium is at its peak.
- **Match**: R → 2 (Maximum amplitude).

4. **Identify the fourth item in List-I (S: Echo)**:
- An echo is the phenomenon where sound waves reflect off a surface and return to the listener.
- This is a direct result of the reflection of sound waves.
- **Match**: S → 4 (Reflection of sound waves).

### Final Matches:
- P → 3 (Velocity of sound is independent of pressure)
- Q → 1 (Nodes have minimum amplitude)
- R → 2 (Antinodes have maximum amplitude)
- S → 4 (Echo is the reflection of sound waves)

### Conclusion:
The final answer is:
- P: 3
- Q: 1
- R: 2
- S: 4