wave_mechanics organ_pipe_vibration_of_air_column Question 12

Question: An organ pipe $ P _{1} $ closed at one end vibrating in its first overtone and another pipe $ P _{2} $ open at both ends vibrating in its third overtone are in resonance with a given tuning fork. The ratio of lengths of $ P _{1} $ and $ P _{2} $ is

[EAMCET 1997; MH CET 1999; AFMC 2001]

Options:

A) 1 : 2

B) 1 : 3

C) 3 : 8

D) 3 : 4

Show Answer

Answer:

Correct Answer: C

Solution:

First overtone of closed organ pipe $ n _{1}=\frac{3v}{4l _{1}} $ Third overtone of open organ pipe $ n _{2}=\frac{4v}{2L _{2}} $

$ n _{1}=n _{2} $ (Given) $ \Rightarrow $ $ \frac{3v}{4L _{1}}=\frac{4v}{2L _{2}}\Rightarrow $

$ \frac{L _{1}}{L _{2}}=\frac{3}{8} $