What is organ pipe? Describe various modes of vibration of an open organ pipe. Compare its fundamental frquency with fundamental frquency of closed organ pipe

General formula for wavelength λ = 2L/n where n = 1,2,3 ………

(1) First normal mode of vibration: n₁ = v/λ₁ = v/2L

This is called fundamental frequency and the note so produced is called fundamental note or first harmonic.

(2) Second normal mode of vibration:

  n₂ = v/λ₂ = v/L = 2(v/2L) = 2n₁ => n₂ = 2n₁

This is called second harmonic or first overtone.

(3) Third normal mode of vibration: n₃ = v/λ₃ = 3v/2L, n₃ = 3n₁

This is called third harmonic or second overtone.