A wave on a stretched string is reflected from a fixed end P of the string. The phase difference, at P, between the incident and reflected waves is

Options

A. zero
B. `pi` rad
C. `pi//2` rad
D. depends on the velocity of the wave

Answer

To solve the problem regarding the phase difference between the incident and reflected waves at a fixed end of a stretched string, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have a stretched string with one end fixed at point P. When a wave travels along the string and reaches the fixed end, it will reflect back.

2. **Identifying the Type of Reflection**:
- Since point P is a fixed end, the wave will undergo a specific type of reflection. In wave physics, the behavior of waves at boundaries is crucial for understanding phase changes.

3. **Applying the Law of Reflection**:
- According to the law of reflection for waves, when a wave reflects off a fixed boundary, it undergoes a phase change.

4. **Determining the Phase Difference**:
- For a wave reflecting off a fixed end, the phase difference between the incident wave and the reflected wave is π radians (or 180 degrees). This means that the reflected wave is inverted compared to the incident wave.

5. **Conclusion**:
- Therefore, the phase difference at point P between the incident and reflected waves is π radians.

### Final Answer:
The phase difference at point P between the incident and reflected waves is π radians.

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