When a column of air is vibrating at the same rate as a tuning fork, the process is referred to as

• A. Refraction
• B. Resonance
• C. Diffraction
• D. Interference

Answer: (B)

Resonance happens when a system is driven at its natural frequency, so it vibrates with the greatest amplitude. A tuning fork pumps energy into the air column at a steady rate. If that rate matches the column’s natural frequency, each push adds to the previous motion just as a push at the right moment would on a swing. The air column then stores more energy, forming a stronger standing wave and producing a louder, clearer vibration.

Refraction is the bending of waves as they change media, not about driving a system at its own frequency. Diffraction is the bending and spreading of waves around obstacles or through openings. Interference involves the superposition of waves producing patterns of reinforcement or cancellation, but none of these describe the selective amplification that occurs when the driving frequency matches the column’s natural frequency.