Question

A closed organ pipe of length 1.2 m vibrates in its first overtone mode. The pressure variation is maximum at :

• A. 0.8 m from the open end
• B. 0.4 m from the open end
• C. at the open end
• D. 1.0 m from the open end

Answer 1

Answer: (B)

0.4 m from the open end

in closed organ pipe in first overtone the pressure is maximum at $\frac{\lambda }{4}$ from the open end and total length will be equal to $\frac{\lambda \times 3}{4}$ .so,

$\frac{\lambda \times 3}{4}=1.2$

$\lambda =1.6$m

so pressure is maximum at $\frac{\lambda }{4}=0.4$m from the open end

so the answer is B.