Question

In a resonance column experiment, a tuning fork of frequency 400 Hz is used. The first resonance is observed when the air column has a length of 20.0 cm and the second resonance is observed when the air column has a length of 62.0 cm. (a) Find the speed of sound in air. (b) How much distance above the open end does the , pressure node form ?

Answer 1

Here given, $I_2=0.62$ m,

$I_1=0.2m,f=400Hz$

We know that,

$\lambda =2(I_2-I_1)$

$\Rightarrow \lambda =2(62-20)=84cm=0.84m$

$\Rightarrow v=n\lambda =0.84\times 400=336m/s$

We know from above that,

$e=\frac{I_2-3I_1}{2}=\frac{62-3\times 20}{2}=1cm$