Question

Why are red coloured lights are used in traffic signals to stop the vehicles?

• A. minimum wavelength and less scatter.
• B. maximum wavelength and more scatter.
• C. maximum wavelength and less scatter.
• D. less wavelength and less scatter.

Answer 1

The correct option is C maximum wavelength and less scatter.

We know among the seven colours of white light, red colour has maximum wavelength. That is why red colour is least scattered by atmospheric dust and other particles. Hence red colour is used to indicated any danger sign.