PDE Q63

The sky appears blue due to a phenomenon called Rayleigh scattering. Among all visible colors, blue light has a shorter wavelength and is scattered in all directions by the gases and particles in the Earth's atmosphere more effectively than other colors. This scattered blue light is what we see when we look at the sky.

• Option A: It is actually blue
  Incorrect. The sky itself is not blue in color; it's an optical effect caused by scattering.

• Option B: The atmosphere scatters blue light more than the others
  Correct. This is the scientific reason behind the blue appearance of the sky.

• Option C: All colours interfere to produce blue
  Incorrect. Color interference is not the cause here.

• Option D: In white light, blue colour dominates
  Incorrect. White light contains all visible wavelengths equally; blue does not dominate.