Answer: 3rd.
- A 2nd
- B 3rd
- C 4th
- D 5th
Correct answer: B. 3rd
Explanation: Closed pipe supports only odd harmonics. Fundamental = 1st harmonic. First overtone = 3rd harmonic.
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.