For scattering of light, the necessary condition is that the size of air molecules should be …………… the wavelength of incident light.

1. smaller than
2. greater than
3. equal to
4. both (b) and (c)

The intensity of scattered light is related to its wavelength as :

1. I ∝ λ⁴
2. I ∝ λ²
3. I ∝ $\dfrac{1}{λ^4}$
4. I ∝ $\dfrac{1}{λ^2}$

Violet light is scattered nearly …………… times more than the red light.

1. 4
2. 8
3. 16
4. 9

To an astronaut in a space-ship, the earth appears —

1. white
2. red
3. blue
4. black