wave_mechanics mock_test_waves_and_acoustics Question 2
Question: An open pipe is in resonance in its $ 2^{nd} $ harmonic with tuning fork of frequency$ f _{1} $ . Now it is closed at one end. If the frequency of the tuning fork is increased slowly from $ f _{1} $ then again a resonance is obtained with a frequency$ f _{2} $ . If in this case the pipe vibrates $ n^{th} $ harmonics then
Options:
A) $ n=3,f _{2}=\frac{3}{4}f _{1} $
B) $ n=3,f _{2}=\frac{5}{4}f _{1} $
C) $ n=5,f _{2}=\frac{5}{4}f _{1} $
D) $ n=5,f _{2}=\frac{3}{4}f _{1} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Open pipe resonance frequency $ f _{1}=\frac{2v}{2L} $ Closed pipe resonance frequency$ f _{2}=\frac{nv}{4L} $
$ f _{2}=\frac{n}{4}f _{1} $ (Where n is odd and$ f _{2}>f _{1} $ ) $ \therefore n=5 $
BETA
