Question

If the fundamental frequency of a pipe closed at one is 512 Hz. The frequency of a pipe of the same dimension but open at both ends will be

• A. 1024 Hz
• B. 512 Hz
• C. 256 Hz
• D. 128 Hz

Answer 1

The correct option is A 1024 Hz

At fundamental frequency of closed organ pipe, the open end will have a node and closed end will have antinode $\frac{\lambda }{4}=L$, where $L$ is length of air column.

$f=\frac{c}{\lambda }$ $=\frac{c}{4L}=512Hz$

At fundamental frequency of open organ pipe, both the open end will have a node $\frac{\lambda }{2}=L$, where $L$ is length of air column.

$f=\frac{c}{\lambda }$ $=\frac{c}{2L}$ $=2\times \frac{c}{4L}=1024Hz$