Question

Two sound waves with wavelengths 5.0 m and 5.5. m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats per second :-

• A. 6
• B. 12
• C. 0
• D. 1

Answer 1

Answer: (A)

6

Answer 2

Number of beats per second
$=\frac{ v }{\lambda_{1}}-\frac{ v }{\lambda_{2}}=330\left(\frac{1}{5}-\frac{1}{5.5}\right)$
$=66-60=6$