During a thunderstorm, the thunder in the skies is produced by the 1. Meeting of cumulonimbus clouds in the sky 2. Lightning that separates the nimbus clouds 3. Violet upward movement of air and water particles. Select the correct answer using the codes given below.

Thunder is the sound produced by the rapid heating and explosive expansion of air surrounding a lightning bolt [3]. When a lightning discharge occurs, it can heat the surrounding air to temperatures as high as 30,000°C [4]. This extreme heat causes the air column to expand at supersonic speeds, creating a shock wave that transitions into the sound waves we perceive as thunder [5]. The provided statements are scientifically inaccurate regarding the direct cause of thunder: it is not produced by the physical meeting of cumulonimbus clouds [4], the separation of nimbus clouds [2], or the upward movement of air and water particles alone. While these convective processes and cloud interactions are essential for generating the electrical charges that lead to lightning [5], the thunder itself is strictly a result of the thermal expansion of air caused by the lightning strike [3].

Sources

1. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 8: Natural Hazards and Disaster Management > Tunderstorms and Hails in India > p. 52
2. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 25: Thunderstorm > 25.4. Lightning And Thunder > p. 349
3. [1] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 6: Pressure, Winds, Storms, and Cyclones > 6.5 Storms, Thunderstorms, and Lightning > p. 91
4. [5] https://www.weather.gov/safety/lightning-science-overview