Key Stage 3 (KS3) Waves Practice Test

Resonance is defined as the phenomenon where a system experiences larger amplitude vibrations when it is subjected to oscillations at its natural frequency. Every physical system has a natural frequency at which it doesn't require much energy to oscillate. When an external periodic force matches this natural frequency, the energy input becomes highly efficient, leading to large oscillations or vibrations.

In the context of various systems, such as musical instruments or bridges, resonance can cause significant amplification of sound or movement, ultimately enhancing the effect. This is why resonance is often used in designs to create powerful sound or movement effects, such as in string instruments or in architecture, where understanding natural frequencies can prevent structural damage.

Other options presented do not accurately describe resonance. Doubling the wave frequency does not necessarily relate to finding a natural frequency or the effects of resonance. Scattering of waves pertains more to their interaction with media and does not express the amplification concept of resonant frequency. Meanwhile, reflection of sound waves refers to the bouncing back of waves from surfaces, which is a separate wave behavior and does not involve natural frequencies or amplitude increase directly associated with resonance.