Which term describes the phenomenon where a system responds most strongly at its natural frequencies?

Which term describes the phenomenon where a system responds most strongly at its natural frequencies?

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

Answer: (C)

When a system can oscillate on its own at a certain frequency, that is its natural frequency. If you drive the system at that same frequency, the input energy is delivered in step with the motion, so each push or input adds energy to the oscillation. Because energy is transferred efficiently in phase with the movement, the amplitude grows larger—this strong response at the natural frequency is called resonance. You can see it in a glass that shivers or even shatters when a sound pitch matches its natural frequency, or a swing going higher when you push at just the right rhythm. The other terms describe different wave behaviors: interference is the combining of waves that can reinforce or cancel each other, diffraction is bending around edges or through openings, and reflection is bouncing off a boundary. None of those specifically capture the amplified response that occurs at a system’s natural frequency.

When a system can oscillate on its own at a certain frequency, that is its natural frequency. If you drive the system at that same frequency, the input energy is delivered in step with the motion, so each push or input adds energy to the oscillation. Because energy is transferred efficiently in phase with the movement, the amplitude grows larger—this strong response at the natural frequency is called resonance. You can see it in a glass that shivers or even shatters when a sound pitch matches its natural frequency, or a swing going higher when you push at just the right rhythm. The other terms describe different wave behaviors: interference is the combining of waves that can reinforce or cancel each other, diffraction is bending around edges or through openings, and reflection is bouncing off a boundary. None of those specifically capture the amplified response that occurs at a system’s natural frequency.