Zaymiey

⚛️ Physics  ·  Waves  ·  NEET & JEE

A closed organ pipe has length L. Fundamental frequency is:

Answer: v/(4L).

  • A v/(4L)
  • B v/(2L)
  • C v/L
  • D 2v/L

Correct answer: A. v/(4L)

Explanation: Closed pipe: closed end is a node, open end is antinode. Fundamental: L = lambda/4, f<sub>1</sub> = v/(4L).

Standing Wave: Nodes and Antinodes (Open Pipe, 2nd Harmonic)nodenodenodeantinodeantinodeSolid and dashed lines show the string/air column at two instants - nodes never move

A standing wave forms from two identical waves travelling in opposite directions and interfering; nodes (always zero displacement) and antinodes (maximum displacement) stay fixed in place, unlike a travelling wave where the whole pattern moves.

Concept context

Wave types, superposition, standing waves, Doppler effect, and sound intensity.

Read the full Waves notes →