RRB Junior Engineer / DMS / CMA 2019 · Question 54 of 3719

Why is red colour preferred for danger signal lights?

Physics - Optics

Aa. Because red colour light has shorter wavelength
Bb. Because red colour is preferred by many
Cc. Because red colour light has longest wavelength and least scattered by fog and smokeCorrect
Dd. Because red colour is bright to eyes

Answer: C. c. Because red colour light has longest wavelength and least scattered by fog and smoke

Explanation

Red color is preferred for danger signal lights because red color light has the longest wavelength and is least scattered by fog and smoke. This makes red light more visible over longer distances and in adverse weather conditions, ensuring that warning signals are clear and noticeable.

Source: RRB JE 2019 CBT-1 (24-May-2019 Shift-2) — ixambee compilation with answer key and solutions · reliable-secondary

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