Q.

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the same length is        [2023]

1 1 : 3  
2 3 : 1  
3 1 : 2  
4 2 : 1  

Ans.

(4)

Fundamental frequency for open organ pipe,

fo=v2Lo                                             ...(i)

Fundamental frequency for closed organ pipe,

fc=v4Lc                                            ...(ii)

fofc=v2Lo×4Lcvfofc=21           (Lo=Lc (given))