Question 7 - MCQs from NCERT Exemplar - Chapter 11 Class 10 - Human Eye and Colourful World

The clear sky appears blue because

(a) blue light gets absorbed in the atmosphere

(b) ultraviolet radiations are absorbed in the atmosphere

(c) violet and blue lights get scattered more than lights of all other colours by the atmosphere

(d) light of all other colours is scattered more than the violet and blue colour lights by the atmosphere

Answer.

The sky appears to have blue color respectively because Earth’s atmosphere scatters the colours of the white light from the sun.

The colours we see are the ones left after the scattering. The phenomenon is called Rayleigh Scattering. 

• Rayleigh scattering is inversely dependent upon wavelength.
• The colours with the smaller wavelengths are scattered more. 
• The violet and blue colors are scattered through the atmosphere and fall in our eyes
• The blue light reaching our eyes makes the sky appear blue.  

So, the correct answer is (c)