Find the fundamental, first overtone and second overtone frequencies of an open organ pipe of length 20 cm. Speed of sound in air is 340 m s-1.
Given:
Speed of sound in air v = 340 m/sec
Length of open organ pipe L = 20 cm = 20 × 10−2 m
Fundamental frequency 
of an open organ pipe:
First overtone frequency 
:
Second overtone frequency 
:
1