Question

An open organ pipe has a fundamental frequency of `300 H_(Z)` . The first overtone of a closed organ pipe has the same frequency as the first overtone of this open pipe . How long is each pipe ? (Speed of sound in air = `330 m//s`)

Answer 1

Correct Answer - C
Fundamental freqency of an open organ pipe, `f_(1)= (nu)/(2l_(0)) rArr l_(0) = (nu)/(2f_(1)) = (330)/(2xx300)`
= `0.55m`
= `55 cm` Given, first overtone of closed organ pipe = first overtone of open organ pipe
Hence, `3((nu)/(4l_(C))) = 2((nu)/(2l_(0)))`
`:. l_(C) = (3)/(4) l_(0) = ((3)/(4)) (0.55)`
= `0.4125 m`
= `41. 25 cm`