Question

The danger signs made red in color, because
(a) the red light can be seen from farthest distance
b) the scattering of red light is least
(c) both (a) and (b)
(d) none of these

Answer 1

The danger signs are made in red color because option (c) both (a) and (b)

- the red light can be seen from the farthest distance and the scattering of red light is the least.

Explanation:

• Danger signals are red in color because it is scattered the least by fog or smoke particles.
• The effect of scattering is inversely proportional to the fourth power of the wavelength of a color.

                       Effect of scattering ∝ $\frac1{\lambda^4}$

• Since the color red has the highest wavelength of all the colors, it is easily visible even from the longest distance.
• This is due to the fact that red light is used as a danger signal as it is able to travel the longest distance through fog or rain, etc.

Answer 2

Answer:

The danger signs are made in red color because option (c) Both (a) and (b).