Question

Give reason: Danger signals are red in colour

Answer 1

Answer:

As the light travels through the atmosphere, tiny air particles scatter it. The dispersion of the light is inversely proportional to the fourth power of its wavelength. Because the red light has the largest wavelength of all colours, it is the least dispersed. Because of this, much of the light gets reflected and can travel longer distances through clouds, fog, dust etc., to enter our eyes effectively.

Explanation

• Danger signs are red because air, water, and dust molecules scatter red light the least.
• Scattering has an inverse relationship with the fourth power of the wavelength of a particular colour. Because red has the longest wavelength of all the colours, it is the least dispersed.
• As a result, red light is utilised as a warning signal since it can travel the most significant distance through the fog, rain, and other conditions without being scattered or fading away.
• According to the Rayleigh equation, light scattering is inversely proportional to the fourth power of the wavelength of light, which implies that shorter wavelengths in visible white light (violet and blue) are dispersed greater than longer wavelengths near the visible spectrum’s red end.
• Rayleigh scattering occurs when dispersing particles are substantially small compared to the wavelength of light.

Refer more:

1. What is the difference between Dispersion and Scattering of Light?
2. Explain dispersion and scattering of light