Question
Physics Question on Waves
An open organ pipe is closed suddenly with the result that the second overtone of the closed pipe is found to be higher in frequency by 100 than the first overtone of the original pipe. Then the fundamental frequency of the open pipe is
A
200s−1
B
100s−1
C
300s−1
D
250s−1
Answer
200s−1
Explanation
Solution
Frequency of second overtone (fifth harmonic) of closed pipe =4l5v .
Frequency of first overtone (second harmonic) of open pipe =2l2v
Accordingly, 4l5v−2l2v=100
Or 4lv=100
Or v=400l
Fundamental frequency of open pipe =2lv=2l400l=200s−1