When a wave travels from a denser to rarer medium, then

Options

A. speed of wave increases
B. wavelength of wave decreases
C. amplitude of wave increases
D. there is no change in phase angle

Explanation

To solve the question regarding the behavior of a wave when it travels from a denser medium to a rarer medium, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Medium Transition**:
- When a wave travels from a denser medium (like water) to a rarer medium (like air), the properties of the wave change due to the difference in density.

2. **Change in Speed**:
- In a denser medium, the speed of the wave is lower compared to a rarer medium. When the wave enters the rarer medium, its speed increases.
- **Conclusion**: The speed of the wave increases.

3. **Change in Wavelength**:
- The wavelength of a wave is directly related to its speed and frequency (v = fλ). Since the frequency remains constant when transitioning between media, an increase in speed results in an increase in wavelength.
- **Conclusion**: The wavelength of the wave increases.

4. **Change in Amplitude**:
- The amplitude of the wave can change depending on the absorption characteristics of the medium. When transitioning from a denser to a rarer medium, the amplitude can increase due to less absorption.
- **Conclusion**: The amplitude of the wave may increase.

5. **Change in Phase**:
- The phase of the wave does not necessarily change when it transitions from one medium to another. The wave continues its propagation without a phase shift.
- **Conclusion**: There is no change in the phase of the wave.

6. **Final Summary**:
- Speed of the wave: Increases
- Wavelength of the wave: Increases
- Amplitude of the wave: May increase
- Phase of the wave: No change

### Final Answer:
- The correct statements regarding the wave traveling from a denser to a rarer medium are:
- Speed increases
- Wavelength increases
- Amplitude may increase
- No change in phase