Question

In closed organ pipe, the resonance consecutive frequencies are in ratio 1 : 3 : 5… and 5^th harmonic frequency is 405 Hz. Velocity of sound = 345 m/s. Find length of organ pipe. 

(1) 108/115 m

(2) 81/115 m

(3) 115/108 m

(4) 115/81 m

Answer 1

(3) 115/108 m

For 5^th harmonic, f = 5f₀ = 405

\(I=\frac{115}{118}m\)