question_answer

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

A) 0.4 m from the open end

B) 0.4 m from the closed end

C) Both (a) and (b)

D) 0.8 m from the open end

Correct Answer: A

Solution :

In first overtone mode \[l=\frac{3\lambda }{4}\] \[\therefore \]  \[\frac{\lambda }{4}=\frac{l}{3}\] \[=\frac{1.2}{3}=0.4m\] Pressure variation will be maximum at displacement nodes, ie, at 0.4 m from the open end.