Which one of the following statements is true ?

Options

A. Both light and sound waves in air are transverse
B. The sound waves in air are longitudinal while the light waves are transverse
C. Both light are sound waves in air are longitudinal
D. Both light and sound waves can travel in vacuum .

Answer

To determine which statement is true regarding the nature of light and sound, we will analyze each statement based on the properties of waves.

### Step-by-Step Solution:

1. **Understanding Wave Types**:
- Waves can be classified into two categories based on the medium required for propagation:
- **Mechanical Waves**: These require a medium to travel through (e.g., sound waves).
- **Non-Mechanical Waves**: These do not require a medium and can travel through a vacuum (e.g., light waves).

2. **Identifying Wave Propagation**:
- Waves can also be classified based on their mode of propagation:
- **Transverse Waves**: The particle displacement is perpendicular to the direction of wave propagation (e.g., light waves).
- **Longitudinal Waves**: The particle displacement is parallel to the direction of wave propagation (e.g., sound waves).

3. **Analyzing the Statements**:
- **Statement 1**: "Both light and sound waves in air are transverse waves."
- **Analysis**: This statement is incorrect because sound waves are longitudinal waves.

- **Statement 2**: "The sound waves in air are longitudinal while the light waves are transverse."
- **Analysis**: This statement is correct. Sound waves are indeed longitudinal, and light waves are transverse.

- **Statement 3**: "Both light and sound waves in air are longitudinal."
- **Analysis**: This statement is incorrect because light waves are transverse, not longitudinal.

- **Statement 4**: "Both light and sound can travel in a vacuum."
- **Analysis**: This statement is incorrect because sound cannot travel in a vacuum; it requires a medium.

4. **Conclusion**:
- After analyzing all the statements, we find that **Statement 2** is the only true statement: "The sound waves in air are longitudinal while the light waves are transverse."

### Final Answer:
The correct statement is: **Statement 2** - "The sound waves in air are longitudinal while the light waves are transverse."

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