Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : The sky is blue due to scattering of sunlight.
Reason (R) : The sky reflects the sea and ocean, which are blue.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Rayleigh scattering explains why the sky is blue during the day, and also why it turns red/orange at sunrise and sunset. At these times, sunlight must travel through a thicker layer of atmosphere, which scatters away the shorter blue wavelengths before the light reaches our eyes.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The color of the sky is determined by how solar electromagnetic radiation interacts with gas molecules and suspended particulates in the Earth's atmosphere.

Step 3: Detailed Explanation:
Let us evaluate both statements individually:
- Assertion (A): This statement is correct.
Sunlight (white light) consists of a spectrum of wavelengths.
As sunlight enters the Earth's atmosphere, it collides with nitrogen and oxygen molecules.
According to Rayleigh scattering, the intensity of scattered light is inversely proportional to the fourth power of its wavelength:
\[ I \propto \frac{1}{\lambda^4} \]
Because blue and violet light have much shorter wavelengths than red or orange light, they are scattered in all directions much more intensely.
Our eyes are more sensitive to blue light (and the upper atmosphere absorbs some violet), which makes the sky appear blue.
- Reason (R): This statement is incorrect.
The sky does not appear blue because it reflects the oceans.
In fact, the relationship is the opposite: large bodies of water like the seas and oceans appear blue primarily because they reflect the blue sky and because water molecules selectively absorb longer (red) wavelengths of light.
Thus, (A) is true but (R) is false.

Step 4: Final Answer:
The correct option is (C) as (A) is true but (R) is false.