Please anybody answer this question....

Question

In a closed organ pipe, the first resonance occurs at 50cm.At what length of pipe , the  second  resonance  will occur

Ans- 150cm

Answer 1

The second resonance will take place at 150cm

Explanation:

As given that first resonance occurs at l = 50 cm
Let's see when fist overtone takes place in a closed organ pipe:

But the λ is calculated for:

From the above figure, it is clear that l = λ/4
But for second overtone let the length be L,

 

Then, L = 3λ/4
L = 3l
L = 3 x 50 = 150 cm