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

Answer

D

Explanation

`f_("open")=(v)/(2l)` [fundamental frequency]
`f_("closed")=(3v)/(4l)` [`3^(rd)` harmonic]
Given, `(3v)/(4l)=100+(v)/(2l)implies(v)/(4l)=100implies(v)/(2l)=200Hz`.