What is the S.I unit of the refractive index?

A. meter

B. kg

C. watt

D. no unit

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Explanation:

What Is Refraction:
Refraction is the bending of light. It occurs when light moves from one medium to another, causing it to slow down or speed up. The refractive index is a measure of how much refraction or bending of light occurs.

What is the S.I unit of the refractive index?

Reason:

The refractive index has no units due to the same quantities. These units cancel each other when calculating the value.