Question

The frequency of sound in oxygen at room temperature is $v$. The frequency of sound in a mixture of oxygen and hydrogen at the same temperature will be

• A. uncertain.
• B. equal to $v$
• C. less than $v$
• D. more than $v$

Answer 1

Answer: (D)

more than $v$

The speed of sound in gas is inversely proportional to the square root of mass of gas. The atomic weight of oxygen is 16 and that of hydrogen is 1.
Hence, the speed of sound in oxygen is less than in hydrogen (ratio of speed of sound in hydrogen to the oxygen is 4:1).
Since the frequency is directly proportional to the velocity of sound hence, for a mixture of oxygen and hydrogen molecules frequency of sound increases than the frequency for oxygen only i.e. $\nu$.