⚛️ Physics · Waves · NEET & JEE

The second harmonic of an open organ pipe has the same frequency as the third harmonic of a closed organ pipe. The ratio of the length of the open pipe to that of the closed pipe is:

Answer: 4/3.

A 3/4
B 2/3
C 3/2
D 4/3

Correct answer: D. 4/3

Explanation: Open pipe 2nd harmonic = 2(v/2Lo) = v/Lo; closed pipe 3rd harmonic = 3(v/4Lc) = 3v/4Lc. Equating gives Lo/Lc = 4/3.

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.

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The second harmonic of an open organ pipe has the same frequency as the third harmonic of a closed organ pipe. The ratio of the length of the open pipe to that of the closed pipe is:

Concept context

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