Question

The two successive natural frequencies of an organ pipe closed at one-end and
open at the other are 700 Hz and 900 Hz respectively. Neglect end correction and
take the speed of sound in air as 320 m/s. The length of the pipe is found to be 10n
cm. Find the value of n.​

Answer 1

Given :

Frequency 1 = 700Hz

Frequency 2 = 900 Hz

Speed of sound in air = 320m/s

To find :

The value of n

Solution:

• we know the relation,  f₀ = f₂ - f₁

                                        = 900 - 700    = 200 Hz

• Wavelength = v/f₀

                    =320/200   = 1.6m

• Length of pipe = wavelength / 2

                        = 0.8m = 80cm

• From the question 10n = 80

                               n = 8

The value of n is 8