Question

A cylindrical tube, open at both ends, has a fundamental frequency `f` in air . The tube is dipped vertically in water so that half of its length is in water. The fundamental frequency of the air column is now
(a) `f // 2`
(b) `3 f // 4`
(C ) `f`
(d) `2f`

Answer 1

Initially , the tube was open at both ends and then it is closed.
`f_(0) = (nu)/2l_(0)` and `f _(C) = (nu)/(4l_(C))` Since, tube is half dipped in water , `l_(C) = (l_(0))/(2)`
`f _(C) = (nu)/(4((l_(0))/(2))) = (nu)/(2l_(0)) = f_(0) =f` Hence, the correct option is (C ).