Free Organ Pipes MCQs with Answers

2 Organ Pipes MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

2 questions

1. In a pipe closed at one end, the fundamental note has

  • A. a node at the closed end and an antinode at the open end
  • B. antinodes at both ends
  • C. nodes at both ends
  • D. an antinode at the closed end

Explanation: The air cannot move at a closed end, so a node forms there, while the open end is free to vibrate and carries an antinode. The pipe therefore holds a quarter of a wavelength at its fundamental, so the wavelength is four times the length. A pipe open at both ends holds half a wavelength and sounds an octave higher for the same length.

Correct answer: a node at the closed end and an antinode at the open end

2. A closed organ pipe produces

  • A. all harmonics
  • B. only even harmonics
  • C. only odd harmonics
  • D. no harmonics at all

Explanation: The node and antinode boundary conditions can only be satisfied by odd multiples of the fundamental, so a closed pipe gives the first, third, fifth and so on. An open pipe supports every harmonic, which is why it sounds richer. This difference in harmonic content is a large part of why a clarinet and a flute have such different tone.

Correct answer: only odd harmonics