Wave Mechanics Question 614

Question: A closed organ pipe (closed at one end) is excited to support the third overtone. It is found that air in the pipe has

Options:

A) three nodes and three antinodes

B) three nodes and four antinodes

C) four nodes and three antinodes

D) four nodes and four antinodes

Show Answer

Answer:

Correct Answer: D

Solution:

[d] Third overtone has a frequency 7n, which means $ L=\frac{7\lambda }{4} $ = three full loops + one half loop, which would make four nodes and four antinodes.