Give Reason Danger Signals are Red in Colour

Answer – It is stated that the dispersion of light is inversely proportional to the fourth power of its wavelength. The red light is least dispersed because it has the largest wavelength of all colours.

Explanation-

Danger signals are indicated by red colour as it is scattered the least by the air molecules. Thus, it can travel longer distances through clouds, fog, rain, etc.  When dispersing particles are substantially small compared to the wavelength of the light then Rayleigh scattering is said to occur.