CBSE-XI-Physics
16: Sound Wave
- #11A cylindrical tube, open at both ends, has a fundamental frequency v. The tube is dipped vertically in water so that half of its length is inside the water. The new fundamental frequency is
(a) v/4
(b) v/2
(c) v
(d) 2v.digAnsr: cAns : c) Ï…
If v is the velocity of the wave and L is the length of the pipe,
then the fundamental frequency for an open organ pipe is
`` \nu =\frac{v}{2L}``
For a closed organ pipe of length L' = L/2, the fundamental frequency is
`` \nu =\frac{v}{4L\text{'}}=\frac{v\times 2}{4\times L}=\frac{v}{2L}=v``
(When the pipe is dipped in water, it behaves like a closed organ pipe that is half the length)
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