wave_mechanics organ_pipe_vibration_of_air_column Question 3

Question: A closed pipe and an open pipe have their first overtones identical in frequency. Their lengths are in the ratio

[Roorkee 1999]

Options:

A) 1 : 2

B) 2 : 3

C) 3 : 4

D) 4 : 5

Show Answer

Answer:

Correct Answer: C

Solution:

If is given that First over tone of closed pipe = First over tone of open pipe

Therefore $ 3( \frac{v}{4l _{1}} )=2( \frac{v}{2l _{2}} ) $ ; where l1 and l2 are the lengths of closed and open organ pipes hence $ \frac{l _{1}}{l _{2}}=\frac{3}{4} $