Physics
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.
Answer
Yellow light has a longer wavelength, so it scatters less in fog and penetrates farther.
Reason — Vehicles use yellow fog lights because yellow light has a longer wavelength and therefore undergoes less scattering in fog which allows it to penetrate farther through water droplets, improving visibility compared to white light.
Related Questions
The danger signal is red because its wavelength is the …………… and therefore it gets ………… the least.
- least, deviated
- longest, scattered
- longest, dispersed
- least, scattered
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.
When sunlight enters the earth's atmosphere, state which colour of light is scattered (i) the most, and (ii) the least.
A beam of blue, green and yellow light passes through the the Earth's atmosphere. Name the colour which is scattered (a) the least, (b) the most.