An open pipe is suddenly closed at one end with the result that the frequency of third harmonic of the closed pipe is found to be higher by `100 Hz` then the fundamental frequency of the open pipe. The fundamental frequency of the open pipe is

Options

A. `200 Hz`
B. `300 Hz`
C. `240 Hz`
D. `480 Hz`

Answer

A

Explanation

`(lambda)/(2) = lambda , :. lambda = 2l`
`n_(1) = (V)/(2l)`
`(3lambda)/(4) = llambda = (4l)/(3)`
`n_(2) = (3V)/(4l)`
`n_(2) = (3V)/(4l)`
`n_(2) - n_(1) = 100`
`(3V)/(4l) - (2V)/(4l) = (100)`
`(V)/(4l) = 100`

Fundamental frequency of open organ pipe `(V)/(2l) = 200 Hz`.