1. The effectiveness with which small particles scatter light depends on the size of the particles and the wavelength of the incident light.
2. Red light has the longest wavelength and hence is scattered least by fog or smoke.
3. Hence, red light can be clearly seen even from a distance. So, danger signal lights are usually red in colour.
2. Red light has the longest wavelength and hence is scattered least by fog or smoke.
3. Hence, red light can be clearly seen even from a distance. So, danger signal lights are usually red in colour.
