Question

A tube of length L₁ is open at both ends. A second tube of length L₂ is closed at one end and open at the other end. This second tube resonates at the same fundamental frequency as the first tube. What is the value of L₂?

A) 4L₁ 

B) 2L₁ 

C) L₁ 

D) ½ L₁ 

E) ¼ L₁

Answer 1

The correct option is: (D) ½ L₁ 

Explanation:

we should look at the harmonic shapes open–open vs open–closed.

Comparing the fundamental harmonic of the open–open pipe to the closed–open pipe. The closed–open pipe should be half as long as the open–open pipe in order to fit the proper number of wavelengths of the same waveform to produce the given harmonic in each.