Question

Sky appears to be blue in clear atmosphere due to light??

• A. scattering
• B. diffraction
• C. dispersion
• D. all of these

Answer 1

Answer: (A)

scattering

Answer 2

On a clear atomsphere, the scattering centres are mainly the air molecules whose dimension is of the order of the wavelenth of light. We know that amount of scattering is proportional to $\frac{1}{\lambda^{4}}.$ Hence red light is the least scattered and more scattering occurs towards the blue end of the spectrum. And on a clear day, as light (blue end) is scattered uniformaly, the sky appears blue.