Question

A closed organ pipe has length $L$. The air in it is vibrating in third overtone with maximum amplitude $a$. The amplitude at distance $\frac{L}{7}$ from closed end of the pipe is :

• A. $0$
• B. $a$
• C. $\frac{a}{2}$
• D. Data insufficient

Answer 1

The correct option is B $a$

closed organ pipe is in third overtone so total length will be equal to $\frac{\lambda \times 7}{4}$ .so,

$\frac{\lambda \times 7}{4}=L$

$\frac{L}{7}$= $\frac{\lambda }{4}$

amplitude at $\frac{\lambda }{4}$ from the closed end is maximum

so amplitude at $\frac{L}{7}$ is $a$.

so the answer is B.