A 30 cm long organ pipe is filled with air and is open at one end and closed at the other. The speed of sound in air at 0°C is 331 m/s. What is the wavelength of the fundamental mode?
A) 1.4 m
B) 1.6 m
C) 1.8 m
D) 1.0 m
E) 1.2 m

Question

Quizplus · Accepted Answer

For a pipe that is open at one end and closed at the other, the fundamental frequency corresponds to a quarter wavelength fitting into the pipe. Therefore, the length of the pipe, $L$, is equal to $\lambda/4$, where $\lambda$ is the wavelength. Solving for $\lambda$, we get $\lambda = 4L$. Given that $L = 30$ cm = 0.3 m, the wavelength $\lambda = 4 \times 0.3$ m = 1.2 m.

A 30 Cm Long Organ Pipe Is Filled with Air