When a wave travels from one medium to another, the quality which will not change is its

Options

A. Amplitude
B. Velocity
C. Frequency
D. Intensity

Explanation

To solve the question "When a wave travels from one medium to another, the quality which will not change is its ___," we need to analyze the properties of waves and how they behave when transitioning between different media.

### Step-by-Step Solution:

1. **Understanding Wave Properties**: Waves have several properties, including velocity, frequency, wavelength, amplitude, and intensity. When a wave travels from one medium to another, some of these properties can change.

2. **Identifying Changing Properties**:
- **Velocity**: The speed of a wave changes when it moves from one medium to another. For example, light travels faster in air than in glass, and sound travels faster in solids than in gases.
- **Wavelength**: The wavelength of the wave also changes when it enters a new medium. This is related to the change in velocity.
- **Amplitude**: The amplitude can change depending on the medium, but it is not a consistent change across all mediums.
- **Intensity**: Intensity can change due to absorption or reflection at the boundary of the two media.

3. **Identifying the Unchanging Property**:
- **Frequency**: The frequency of the wave remains constant when it travels from one medium to another. This is because frequency is determined by the source of the wave and does not change with the medium.

4. **Conclusion**: Therefore, the quality that will not change when a wave travels from one medium to another is its **frequency**.

### Final Answer:
The quality which will not change is its **frequency**.

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