Assertion : Focal length of a spherical mirror does not depend on the material from which mirror is made but same for the lens depends on the material of lens.
Reason : Law of reflection does not depend on material and surrounding medium but law of refraction depends on refractive index of the materials.

Options

A. If both assertion and reason are correct and rason is a correct explanation of the assertion.
B. If both assertion and reason are correct but reason is not the correct explanation of assertion.
C. If assertion is correct but reason is incorrect.
D. If assertion is incorrect but reason is correct.

Answer

To analyze the given assertion and reason, we will break down the concepts involved step by step.

### Step 1: Understanding the Assertion
**Assertion:** The focal length of a spherical mirror does not depend on the material from which the mirror is made, while for a lens, it does depend on the material of the lens.

- **Explanation:** The focal length of a spherical mirror is determined by its shape (radius of curvature) and not by the material. This is because mirrors reflect light based on the law of reflection, which is independent of the material of the mirror.

### Step 2: Understanding the Reason
**Reason:** The law of reflection does not depend on material and surrounding medium, but the law of refraction depends on the refractive index of the materials.

- **Explanation:** The law of reflection states that the angle of incidence is equal to the angle of reflection, which holds true regardless of the material of the mirror or the medium surrounding it. On the other hand, the law of refraction (Snell's Law) states that the bending of light as it passes from one medium to another depends on the refractive indices of the two media involved, which are material-dependent.

### Step 3: Evaluating the Assertion and Reason
- Both the assertion and the reason are correct.
- The reason provided correctly explains why the assertion holds true: the focal length of mirrors is not influenced by material properties, while lenses are affected due to their dependence on refractive indices.

### Conclusion
Both the assertion and reason are correct, and the reason is indeed the correct explanation for the assertion.

### Final Answer
**A. Both assertion and reason are correct, and reason is the correct explanation of the assertion.**

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