Question

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

Answer 1

Correct Answer - A
`f_(1)lamda_(1)=v`
`f_(1)((4L)/(3))=vrArrf_(1)=(3v)/(4L),f_(2)(2L)=vrArrf_(2)=(v)/(2L)`
Given that `f_(1)-f_(2)=100`
`rArr (3v)/(2L)-(v)/(2L)=100 rArr(v)/(2L)=200Hz`