UPSEE Solved Model Paper 6

Let l be the length of the pipes and v the speed of sound. The frequency of open organ pipe of nth overtone is
f1 = (n+1)v/2l
and frequency of closed organ pipe of nth overtone is
f2 = (2n+1)v/4l
∴ The desired ratio is

f1

f2

= 2(n+1)/2n+1