Assertion Sun appears red during sunrise and sunset due to the phenomenon of refraction.
Reason In refraction of light frequency of light remains unchanged.

Options

A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If Assertion is false but Reason is true.

Answer

To solve the assertion-reason question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "the Sun appears red during sunrise and sunset due to the phenomenon of refraction."

- **Explanation**: When sunlight passes through the Earth's atmosphere, it encounters different layers of air with varying densities. This causes the light to bend or refract. During sunrise and sunset, the sunlight has to pass through a larger thickness of the atmosphere compared to when it is overhead. As a result, shorter wavelengths of light (like blue and violet) scatter more due to Rayleigh scattering, while the longer wavelengths (like red and orange) are less affected and reach our eyes. This is why the Sun appears red during these times.

### Step 2: Understand the Reason
The reason states that "in refraction of light, the frequency of light remains unchanged."

- **Explanation**: When light refracts, its speed and wavelength change depending on the medium it travels through, but its frequency remains constant. This is because frequency is determined by the source of the light and does not change when light passes from one medium to another.

### Step 3: Evaluate the Truth of Both Statements
- The assertion is true because the Sun does appear red during sunrise and sunset due to the refraction of light in the atmosphere.
- The reason is also true because the frequency of light does remain unchanged during refraction.

### Step 4: Determine the Relationship
Since both the assertion and the reason are true, and the reason correctly explains the assertion, we conclude that both statements are true and the reason is the correct explanation for the assertion.

### Final Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion.

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