Question

What is the second lowest resonant frequency for a 0.7 m long organ pipe closed at one end? e) 515 Hz d) 368 Hz c) 405 Hz b) 429 Hz a) 322 Hz

Answer 1

(d) 368 Hz

Step-by-step explanation:

The resonance frequency of one closed end pipe is given by
`f=(nv)/(4L)` where n =1,3,5,7------------

Here we are talking about second lowest resonant frequency so n=3

The speed of sound v = 343 m/sec

Length of pipe L =0.7 m

So
`f=(nv)/(4L)=(3* 343)/(4* 0.7)=367.5\ Hz`

Which is closest to 368 Hz so option (d) will be the correct answer