wave_mechanics organ_pipe_vibration_of_air_column Question 46
Question: Two closed organ pipes of length 100 cm and 101 cm 16 beats in 20 sec. When each pipe is sounded in its fundamental mode calculate the velocity of sound
[AFMC 2003]
Options:
A) 303 ms?1
B) 332 ms?1
C) 323.2 ms?1
D) 300 ms?1
Show Answer
Answer:
Correct Answer: C
Solution:
Number of beats per second, $ n=\frac{16}{20}=\frac{4}{5} $
Therefore $ n=n _{1}-n _{2}=\frac{v}{4}( \frac{1}{l _{1}}-\frac{1}{l _{2}} ) $
Therefore $ \frac{4}{5}=\frac{v}{4}( \frac{1}{1}-\frac{1}{1.01} )=\frac{0.01v}{4\times 1.01} $
$ v=\frac{16\times 101}{5}=323.2m{{s}^{-1}} $
BETA
