Physics
During the day the sky appears blue, while during sunset it appears reddish. Which reason correctly explain this phenomenon?
- Blue light has higher wavelength, so it gets scattered more during the day.
- Blue light has shorter wavelength, so it gets scattered more during the day.
- Scattering depends only on the intensity and not on the wavelength of the light.
- Red light has shorter wavelength, so it gets scattered more at sunset.
Answer
Blue light has shorter wavelength, so it gets scattered more during the day.
Reason — During the day, the sky appears blue because blue light has a shorter wavelength and is scattered more by the atmosphere. At sunset, sunlight travels a longer path, so most blue light is scattered away and longer wavelengths like red dominate, making the sky appear reddish.
Related Questions
To an astronaut in a space-ship, the earth appears —
- white
- red
- blue
- black
The danger signal is red because its wavelength is the …………… and therefore it gets ………… the least.
- least, deviated
- longest, scattered
- longest, dispersed
- least, scattered
Vehicles use yellow fog lights instead of white while driving in foggy conditions. The correct reason for this is :
- White light is absorbed completely by water droplets.
- Yellow light has a shorter wavelength so it scatters more.
- Yellow light has a longer wavelength, so it scatters less in fog and penetrates farther.
- Yellow light has all seven colours in it.
When sunlight enters the earth's atmosphere, state which colour of light is scattered (i) the most, and (ii) the least.