A 30.0 cm long organ pipe is filled with air and is open at one end and closed at the other.The velocity of sound in air at 0$^{\circ}$C is 331 m/s.What is the frequency of the second mode?
A) 900 Hz
B) 827 Hz
C) 750 Hz
D) 721 Hz
E) 650 Hz

Question

Quizplus · Accepted Answer

The second mode of a closed-open organ pipe is given by the equation: 
f = (2n-1) v/4L 
where f is frequency, n is the harmonic number (2 for second mode), v is the velocity of sound, and L is the length of the pipe. 
Substituting the given values, we get: 
f = (2*2-1) * 331/4*0.3 = 826.5 Hz ≈ 827 Hz 
Therefore, the best choice is (B).

A 300 Cm Long Organ Pipe Is Filled with Air and and Is