Question
Download Solution PDFThe flash of lightning is seen before the thunderstorm is heard. It verifies that
This question was previously asked in
UPSC NDA-II (General Ability) Official Paper-I (Held On: 03 Sept, 2023)
Answer (Detailed Solution Below)
Option 2 : light travels much faster than sound
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NDA 01/2025: English Subject Test
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Detailed Solution
Download Solution PDFThe correct answer is Light travels much faster than sound.
Key Points
- Light travels at a much higher speed than sound.
- The speed of light in a vacuum is 3,00,000 km/s, while the speed of sound varies depending on the medium but is much slower (e.g., around 343 meters per second in air).
- When lightning occurs, the light from the flash reaches the observer almost instantaneously, while the sound of thunder takes some time to travel through the air.
- The time gap between seeing the lightning and hearing the thunder can be used to estimate the distance of the lightning strike.
Additional Information
- According to Einstein's special relativity, the speed of light has a unique state: it is a fundamental characteristic of our universe, representing the maximum speed at which information can travel from one place to another.
- The twinkling of a star is due to the atmospheric refraction of starlight.
- The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.
- The atmospheric refraction occurs in a medium of gradually changing refractive index.
- Since the atmosphere bends starlight towards the normal, the apparent position of the star is slightly different from its actual position.
Last updated on Jun 18, 2025
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