Assertion (A): The velocity of sound waves in dry air increases with a rise in the ambient temperature of the gas medium. Reason (R): The speed of sound in an ideal gas is directly proportional to the square root of its absolute temperature.

💡 Solution & Explanation

The speed of sound in a gas is given by Laplace formula as the square root of the ratio of specific heats multiplied by universal gas constant and absolute temperature, divided by molar mass. Since velocity varies directly with the square root of absolute temperature, warming the air increases molecular kinetic energy and sound propagation speed. Sound travels faster in humid air than in dry air because water vapor has a lower molar mass than dry air.