question_answer

A hollow cylinder with both sides open generates a frequency \[f\] in air. When the cylinder vertically immersed into water by half its length the frequency will be

A) \[f\]                                      

B)  \[2f\]

C)  \[f/2\]                 

D)  \[f/4\]

Correct Answer: A

Solution :

                                (i) Here,  \[\frac{\lambda }{2}=l\Rightarrow \lambda =2l\] So,          \[v=\frac{v}{2l}\] (ii) and                  \[\frac{\lambda }{4}=\frac{l}{2}\]                 \[\lambda =\frac{4l}{2}=2l\]                 \[\therefore \]  \[{{v}_{2}}=\frac{v}{2l},\]the same                 \[\therefore \]\[f\]  (original) is the frequency