Match List-I with List-II and select the correct answer using the code given below the lists : List-I (Phenomenon) A. Reverberation B. Resonance C. Refraction List-II (Reason) 1. Occurs when. two waves of equal frequency superpose 2. Occurs when two waves have slightly diffe- rent frequencies superpose 3. Prolonged echo of light 4. Occurs as a ray of light enters a second medium Code : ABC

The phenomenon of reverberation is defined as the persistence of sound in an enclosed space due to multiple reflections, effectively acting as a prolonged echo [t1][t2]. While the question uses the term 'light', in standard physics, reverberation refers to sound persistence [t4]. Resonance occurs when a periodic force drives a system at its natural frequency; in wave mechanics, this is associated with the superposition of waves of equal frequency to form standing waves [t1][t2]. Refraction is the bending of a wave, such as light, as it passes from one transparent medium into another due to a change in speed [c4]. Beats, which are not explicitly listed in the match but correspond to reason 2, occur when two waves of slightly different frequencies superpose. Therefore, A matches 3 (prolonged echo), B matches 1 (equal frequency superposition), and C matches 4 (entering a second medium).

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Activity 9.10 > p. 147