Question

For a particular sound wave propagating in air, a path difference between two points is 0.54 m which is equivalent to phase difference of (1.8 π)c. If the velocity of sound wave in air is 330 m/s, the frequency of this wave is

• A. 110 Hz
• B. 367 Hz
• C. 550 Hz
• D. 660 Hz

Answer 1

Answer: (C)

550 Hz

Answer 2

Phase difference = $\frac {2π}{λ}$ x Path difference
1.8 π = $\frac {2π}{λ}$ x 0.54
λ = $\frac {2π \times 0.54}{1.8 π}$
λ = 0.60 m
Now
v = fλ
f = $\frac {v}{λ }$
f = $\frac {330}{0.60}$
f = 550 Hz
Therefore Correct option is (C)