Assertion : When monochromatic light is incident on a surface separting two media, the reflected and refracted light both have the same frequency as the incident frequency.
Reason: The frequency of monochromatic light depends on media.

Options

A. If both assertion and reason are true and\ reason is a correct explanation of the assertion
B. If both assertion and reason are true but the reason is not a 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 question, we will analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states: "When monochromatic light is incident on a surface separating two media, the reflected and refracted light both have the same frequency as the incident frequency."

- **Monochromatic Light**: This refers to light of a single wavelength and frequency.
- **Behavior at the Interface**: When monochromatic light strikes the boundary between two media, both the reflected and refracted light maintain the same frequency as the incident light. This is because the frequency of light is determined by the source and does not change when light enters a different medium or reflects off a surface.

**Conclusion for Assertion**: The assertion is **True**.

### Step 2: Understand the Reason
The reason states: "The frequency of monochromatic light depends on media."

- **Frequency Dependence**: The frequency of light is a characteristic of the light wave itself and is determined by the source of the light. It does not change when light travels from one medium to another. The speed of light and wavelength may change, but the frequency remains constant.

**Conclusion for Reason**: The reason is **False**.

### Final Conclusion
- The assertion is **True**.
- The reason is **False**.

### Answer
Thus, the correct answer is that the assertion is true, but the reason is false.

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