Which of the following factors does not affect the speed of sound in air?

Explanation

The factor that does not significantly affect the speed of sound in air (under normal conditions) is pressure of gas. Here's why:Temperature: The speed of sound in air is directly proportional to the square root of the absolute temperature. As temperature increases, the speed of sound increases. This is the most significant factor. Moisture in air (Humidity): Increased humidity slightly increases the speed of sound. This is because lighter water molecules replace some of the heavier nitrogen and oxygen molecules in the air, slightly decreasing the density.Density of gas: In general, the speed of sound is inversely proportional to the square root of the density of the medium. However, in an ideal gas, changes in pressure are accompanied by proportional changes in density, so the ratio of pressure to density remains constant at a given temperature. Therefore, pressure itself does not significantly affect the speed of sound in an ideal gas (like air under normal conditions).It's important to note that at extremely high pressures, the ideal gas law no longer holds, and pressure can have a more noticeable effect. However, for everyday conditions, the effect of pressure on the speed of sound in air is negligible. Therefore, the correct answer is Pressure of gas.