Wave Mechanics Question 807
Question: Velocity of sound waves in air is 330 m/sec. For a particular sound in air, a path difference of 40 cm is equivalent to a phase difference of 1.6p. The frequency of this wave is
[CBSE PMT 1990]
Options:
A) 165 Hz
B) 150 Hz
C) 660 Hz
D) 330 Hz
Show Answer
Answer:
Correct Answer: C
Solution:
Phase difference =$ \frac{2\pi }{\lambda }\times $ path difference
Therefore $ 1.6\pi =\frac{2\pi }{\lambda }\times 40 $
$ \Rightarrow $ $ \lambda =50 $
$ cm $ = 0.5m
Therefore $ v=n\lambda $
Therefore $ 330=0.5\times n\Rightarrow n=660,Hz $
BETA
