With decrease in water vapiur content in air velocity of sound

Options

A. increase
B. decrease
C. remains constant
D. nothing can decided

Explanation

To determine the effect of a decrease in water vapor content in air on the velocity of sound, we can follow these steps:

### Step 1: Understanding Humidity
- **Definition of Humidity**: Humidity refers to the amount of water vapor present in the air. When the humidity decreases, it means that there is less water vapor in the air.

### Step 2: Relationship Between Humidity and Density
- **Density of Air**: The density of air is affected by the amount of water vapor it contains. When water vapor is present, it replaces some of the heavier nitrogen and oxygen molecules in the air. Therefore, as humidity decreases (less water vapor), the density of air increases.

### Step 3: Effect of Density on Velocity of Sound
- **Velocity of Sound**: The velocity of sound in a medium is inversely proportional to the square root of the density of that medium. This means that if the density of air increases, the velocity of sound will decrease.

### Step 4: Conclusion
- **Final Statement**: Therefore, when the water vapor content in air decreases, the density of air increases, leading to a decrease in the velocity of sound.

### Final Answer
- The velocity of sound decreases with a decrease in water vapor content in air.

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