Question
Download Solution PDFWhy do danger signals use red light?
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFCONCEPT:
- Scattering of light: The phenomenon in which the light ray is redirected in all other directions on passing through particles of dimensions comparable to the wavelength of the light used is called scattering of light.
- Rayleigh scattering: The scattering of light off of the molecules of the air that can be extended to scattering from particles up to about a tenth of the wavelength of the light used is called Rayleigh scattering.
According to Rayleigh scattering:
Scattering
Where λ is the wavelength of light
For white light:
Order of wavelength:
Violet < Indigo < Blue < Green < Yellow < Orange < Red
EXPLANATION:
- From the Rayleigh scattering, the more the wavelength of radiation, the less it will be scattered.
- Since red light has the longest wavelength, it gets scattered the least and travels more distance, and the intensity of the light is not reduced due to scattering.
- Therefore, red light is used in danger signals so that they can be seen from a distance. Hence option 2 is correct.
Last updated on Jul 9, 2025
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