Which of the following properties of sound is not affected by change in air temperature?

Options

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

Answer

To determine which property of sound is not affected by a change in air temperature, we will analyze the properties of sound: velocity, frequency, wavelength, amplitude, and intensity.

### Step-by-Step Solution:

1. **Understanding the Properties of Sound**:
- **Velocity of Sound**: The speed at which sound travels through a medium.
- **Frequency**: The number of oscillations or cycles per second.
- **Wavelength**: The distance between consecutive points of the same phase in a wave.
- **Amplitude**: The maximum displacement of points on a wave from the rest position.
- **Intensity**: The power per unit area carried by a wave.

2. **Effect of Temperature on Velocity**:
- The velocity of sound in air is affected by temperature. The relationship can be expressed as:
\[ \frac{V_t}{V_0} = \sqrt{\frac{T}{T_0}} \]
- Here, \(V_t\) is the velocity of sound at temperature \(T\), \(V_0\) is the velocity at absolute zero (0 Kelvin), \(T\) is the temperature in Kelvin, and \(T_0\) is the reference temperature.

3. **Effect of Temperature on Frequency**:
- Frequency is related to the velocity of sound. Since velocity changes with temperature, frequency also changes:
\[ f = \frac{V}{\lambda} \]
- Therefore, frequency is affected by temperature changes.

4. **Effect of Temperature on Wavelength**:
- Wavelength is calculated using the formula:
\[ \lambda = \frac{V}{f} \]
- Since both velocity and frequency are affected by temperature, wavelength will also be affected.

5. **Effect of Temperature on Amplitude and Intensity**:
- Amplitude and intensity depend on the nature of the medium (air in this case) and are not directly affected by temperature changes. They remain constant as long as the medium's properties do not change.

6. **Conclusion**:
- The properties of sound that are not affected by changes in air temperature are **Amplitude** and **Intensity**. However, since the question asks for one property, we can conclude that **Amplitude** is the most straightforward answer, as it is not influenced by temperature changes.

### Final Answer:
**Amplitude** is the property of sound that is not affected by a change in air temperature.