Answer: Frequency matches natural frequency.
- A Frequency matches natural frequency
- B Amplitude is maximum
- C Speed is maximum
- D Wavelength equals column length
Correct answer: A. Frequency matches natural frequency
Explanation: Resonance occurs when the driving frequency equals the natural frequency of the system, producing large amplitude vibrations.
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.