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The danger signals installed at the top ...

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

A

is scattered the most by smoke or fog

B

is scattered the least by smoke or fog

C

is absorbed the most by smoke or fog

D

moves fastest in air

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The correct Answer is:
B
The danger signals installed at the top of tall buildings are red in colour because among all other colours, red colour is scattered the least by smoke or fog. This is primarily because wavelength of red colour is the largest. Thus it can be easily seen from a distance.
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NCERT EXEMPLAR-THE HUMAN EYE AND THE COLOURFUL WORLD -The Human Eye And The Colourful World
  1. The clear sky appears blue, because

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  2. Which of the following statements is correct regarding the propagation...

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  3. The danger signals installed at the top of tall buildings are red in c...

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  4. Which of the following phenomena contributes significantly to the redd...

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  5. The blue colour of the water of the sea is due to :

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  6. When light rays enter the eye, most of the refraction occurs at the

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  7. The focal length of the eye lens increases when eye muscles

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  8. Draw ray diagrams each showing (i) myopic eye and (ii) hypermetrop...

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  9. A student sitting at the back of the classroom cannot read clearly the...

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  10. How are we able to see nearby and also the distant objects clearly?

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  11. Nooper needs a lens of power - 4.5 D for correction of her vision. (...

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  12. How will you use two indentical prisms so that a narrow beam of white ...

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  13. Draw a ray diagram showing the dispersion through a prism when a narro...

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  14. Is the position of a star as seen by us its true position? Justify you...

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  15. Why do we see a rainbow in the sky only after rainfall?

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  16. Why does clear sky appear blue ?

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  17. What is the difference in colours of the sun observed during sunrise/s...

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  18. Explain the refraction of light through a triangular glass prism using...

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  19. How can we explain the reddish appearance of sun at sunrise or sunset?...

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  20. Explain the phenomenon of dispersion of white light through a glass pr...

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