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 second mode of vibration?
A) 10 cm
B) 20 cm
C) 30 cm
D) 40 cm
E) 60 cm

Question

Quizplus · Accepted Answer

For a pipe open at one end and closed at the other, the second mode of vibration corresponds to the third harmonic (n=3). The formula for the wavelength ($\lambda$) in this case is $\lambda = \frac{4L}{n}$, where $L$ is the length of the pipe. Substituting $L = 30$ cm and $n = 3$, we get $\lambda = \frac{4 \times 30}{3} = 40$ cm.

A 30 Cm Long Organ Pipe Is Filled with Air