Correct Answer - Option 2 : Scattering of light
CONCEPT:
Rayleigh's law of scattering:
- According to Rayleigh's law of scattering, the intensity of light of wavelength λ present in the scattered light is inversely proportional to the fourth power of λ, provided the size of the scattering particles are much smaller than λ. Mathematically,
\(I \propto \frac{1}{\lambda }\)
- Thus the scattered intensity is maximum for shorter wavelength.
EXPLANATION:
- Clouds are white because light from the Sun is white.
- As light passes through a cloud, it interacts with the water droplets, which are much bigger than the atmospheric particles that exist in the sky.
- When sunlight reaches an atmospheric particle in the sky, blue light is scattered away more strongly than other colours, giving the impression that the sky is blue.
- But in a cloud, sunlight is scattered by much larger water droplets.
- These scatter all colours almost equally meaning that the sunlight continues to remain white and so make the clouds appear white against the background of the blue sky.
- Light entering the Earth's atmosphere gets scattered by coming in contact with atmospheric particles.
- This phenomenon is called the scattering of light.