A pipe opened at both ends prpduces a note of
frequency `f_(1)`. When the pipe is kept with `3/4th` of its
length in water, it produces a note of frequency `f_(2)`.
The ratio `f_(1)/f_(2)` is

Options

A. `4//3`
B. `3//4`
C. 2
D. `1//2`

Answer

B

Explanation

When the pipe of length L open at both the ends, `upsilon_(1)=(v)/(2L)`
When `3//4^(th)` of its length is in water, it behaves as a closed pipe of length `L//4`.
`therefore upsilon_(2)=(v)/(4(L//4))=(v)/(L)` Thus, `(upsilon_(1))/(upsilon_(2))=(1)/(2)`