Select the correct statement about the reflection and refraction of a wave at the interface between the medium 1 and 2 the

Options

A. Reflected wave has a phase change of ` pi`
B. Wavelength of reflected wave is less than that of incident wave
C. Frequency of transmitted wave is same as that of incident wave
D. Frequency of wave changes as per nature of boundary .

Answer

To solve the question regarding the reflection and refraction of a wave at the interface between two media, we will analyze each option provided and determine which statement is correct.

### Step-by-Step Solution:

1. **Understanding Reflection and Refraction:**
- When a wave encounters the boundary between two different media, part of the wave is reflected back into the first medium, and part of it is refracted into the second medium.

2. **Analyzing Option A: "Reflected wave has a phase change of π."**
- The phase change upon reflection depends on the relative densities of the two media.
- If the wave reflects off a denser medium, it undergoes a phase change of π (180 degrees).
- If it reflects off a less dense medium, there is no phase change (0 degrees).
- Therefore, this statement is **not always true**.

3. **Analyzing Option B: "Wavelength of reflected wave is less than that of incident wave."**
- The wavelength of a wave is determined by the medium through which it travels.
- Upon reflection, the wavelength does not change; it remains the same as the incident wave in the same medium.
- Thus, this statement is **incorrect**.

4. **Analyzing Option C: "Frequency of transmitted wave is the same as that of incident wave."**
- The frequency of a wave remains constant when it passes from one medium to another.
- This is a fundamental property of waves; frequency does not change due to the medium.
- Therefore, this statement is **correct**.

5. **Analyzing Option D: "Frequency of wave changes as per nature of medium."**
- As mentioned, the frequency of a wave does not change when transitioning between media.
- This statement is **incorrect**.

### Conclusion:
After analyzing all options, the correct statement is **Option C: Frequency of transmitted wave is the same as that of incident wave.**

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