The fundamental frequency in an open organ pipe is equal tothe third harmonic of a closed organ pipe . If the length of the closed organ pipe is 20 cm , the length of the open organ pipe is

The fundamental frequency in an open organ pipe is equal tothe third h

1.	The fundamental frequency in an open organ pipe is equal tothe third harmonic of a closed organ pipe . If the length of the closed organ pipe is 20 cm , the length of the open organ pipe is
Answer» 12 . 5 cm 8 cm 13 . 2 cm 16 cm SOLUTION :Third harmonic of a CLOSED ORGAN pipe, `n_(2) = (3V)/(4l) ` [ l = length of closed organ pipe V = velocity of sound] Fundamental frequency of open organ pipe, `n_(0) = (V)/(2l^(.)` [`l^(.) =` length of open organ pipe] `:.(3V)/(4l)=(V)/(2l^(.))or, l^(.) = (4l)/(3xx2) = (2l)/(3) = (2xx20)/(3)` or,`l^(.) = 13 . 33` cm