When you speak to your friend which of the following parameters have a unique value in the sound produced?

Options

A. Frequency
B. wavelength
C. Amplitude
D. Wave velocity

Answer

To determine which parameters have a unique value in the sound produced when you speak to your friend, we will analyze the four options provided.

### Step-by-Step Solution:

1. **Understanding the Parameters**: The parameters in question are wave velocity, amplitude, frequency, and wavelength. We need to analyze each one to see if it has a unique value when you speak to your friend.

2. **Wave Velocity**:
- Wave velocity depends on the medium through which the sound travels. Since both you and your friend are in the same medium (air), the wave velocity will be the same for both of you.
- **Conclusion**: Wave velocity has a unique value.

3. **Amplitude**:
- Amplitude refers to the energy of the sound wave. It can vary based on how loudly you or your friend speak. Thus, the amplitude can differ between the two of you.
- **Conclusion**: Amplitude does not have a unique value.

4. **Frequency**:
- Frequency is determined by the size and tension of the vocal cords. Since these can vary between individuals, the frequency of the sound produced can be different for you and your friend.
- **Conclusion**: Frequency does not have a unique value.

5. **Wavelength**:
- Wavelength is inversely proportional to frequency (given a constant wave velocity). Since frequency can vary between you and your friend, the wavelength will also vary accordingly.
- **Conclusion**: Wavelength does not have a unique value.

### Final Answer:
Only wave velocity has a unique value when you speak to your friend. The other parameters (amplitude, frequency, and wavelength) do not have unique values.

### Summary of Correct Options:
- **Correct Option**: Wave Velocity (Option 4)
- **Incorrect Options**: Amplitude (Option 3), Frequency (Option 1), Wavelength (Option 2)