Question

A tube is of shape shown in figure. The straight line portion l₁ = 100 cm and the side tube measures l₂ = 185 cm. Find the audible frequencies for which this device acts as a silencer (speed of sound = 340 m/s).

Answer 1

The path difference,

= 200 (2n – 1) 

Thus for n = 1, 2,..... 

f = 200, 600, 900, Hz. .....