1.

The fundamental frequency of an air column in a pipe closed at one end is in unison with the third overtone of an open pipe. Calculate the ratio of lengths of their air columns.

Answer»

Given: Fundamental frequency for closed pipe = Third overtone of open pipe. 

To find: Ratio of lengths of air columns in both the pipes \((\frac{l_c}{l_o})\) 

Formulae: a. Fundamental frequency of pipe closed at one end: 

nc = \(\frac{v}{4l_c}\) 

b. Fundamental frequency of pipe open at both ends: 

no = \(\frac{v}{2l_o}\) 

c. Third overtone of open pipe: 

n3 = 4n0

Calculation: Fundamental frequency of closed pipe (nc) is same as third overtone of open pipe.

∴ nc = n3 

∴ nc = 4n0 

∴ \(\frac{v}{4l_c}\) = 4[\(\frac{v}{2l_o}\)]

∴ \(\frac{v}{4l_c}\) = \(\frac{2}{l_o}\)

∴ \(\frac{l_c}{l_o}\)\(\frac18\)

The ratio of lengths of air columns in closed pipe and open pipe is 1:8.



Discussion

No Comment Found

Related InterviewSolutions