Answer: 1020 Hz.
- A 340 Hz
- B 1020 Hz
- C 680 Hz
- D 1360 Hz
Correct answer: B. 1020 Hz
Explanation: Fundamental f<sub>1</sub> = v/4L = 340/1 = 340 Hz. A closed pipe first overtone is the third harmonic = 3f<sub>1</sub> = 1020 Hz.
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.