Multiple choice

Danger signals are generally red as red light

  1. Is least bright

  2. Undergoes least deviation

  3. Has lowest velocity

  4. Gives comfort to eye
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Red light is used for danger signals because it undergoes the least deviation (scattering) when passing through atmospheric particles like dust, fog, and water droplets. According to Rayleigh scattering, longer wavelengths (red) scatter less than shorter wavelengths. This makes red light most visible over long distances and in poor visibility conditions.

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