Question

The appearance of the blue color of the sky and reddish color of the sun at sunrise and sunset is due to which phenomenon of light?

• A. Interference
• B. Reflection
• C. Refraction
• D. Scattering

Hint:

Scattering explains colors based on particle size and light path: - Blue Sky: Short-wavelength blue light is scattered more by small air molecules. - Red Sunset: Long path through atmosphere scatters blue light away, leaving red light to pass through. - White Clouds: Larger water droplets scatter all colors equally (Mie scattering).

Answer 1

The Correct Option is D

Step 1: Rayleigh Scattering Explained.Sunlight entering Earth's atmosphere interacts with gas molecules (mainly nitrogen and oxygen), scattering light in all directions. Rayleigh scattering is strongest for shorter wavelengths. Scattering intensity is inversely proportional to the fourth power of the wavelength (\(I \propto 1/\lambda^4\)).

Step 2: Blue Sky and Scattering.Blue and violet light, with the shortest visible wavelengths, scatter most. The scattered blue light from all directions makes the sky appear blue.

Step 3: Sunrise/Sunset and Scattering.At sunrise/sunset, sunlight travels through a thicker atmosphere layer. Most blue/green light is scattered away. Remaining light, rich in red, orange, and yellow wavelengths, makes the sun and surrounding sky appear reddish.