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

B

Explanation

Fundamental frequency of an open pipe is `upsilon_(o)=(v)/(2l)` and that of a closed pipe of the same length is
`upsilon_(c)=(v)/(4L)=(1)/(2)(v)/(2L)=(upsilon_(o))/(2)`
When the open pipe is suddenly closed at one end, as per question
`3upsilon_(c)=upsilon_(o)+100or(3upsilon_(o))/(2)=upsilon_(o)+100orupsilon_(o)=200Hz`