Question

A tube closed at one end containing air produces a fundamental note of frequency 512Hz. If the tube is open at both ends, the fundamental frequency will be __________

(a) 256Hz

(b) 768Hz

(c) 1024Hz

(d) 1280Hz

This question was addressed to me in an online quiz.

This interesting question is from Acoustics topic in section Waves of Engineering Physics I

Answer 1

Correct option is (c) 1024Hz

For explanation: Fundamental frequency of a closed pipe,

γ=v/4L=512Hz

Fundamental frequency of open pipe,

γ^‘=v/2L=2γ=2×512=1024Hz.