Absolute refractive index of a material depends upon

Options

A. nature of material
B. nature, wavelength and size of material
C. density, temperature, wavelength of material
D. fiature, temperature, wavelength of material

Answer

To determine the absolute refractive index of a material and what it depends on, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Refractive Index**:
- The refractive index (n) of a medium is defined as the ratio of the speed of light in vacuum (c) to the speed of light in the medium (v). Mathematically, it is given by:
\[ n = \frac{c}{v} \]

2. **Nature of Material**:
- The refractive index is primarily dependent on the nature of the material. Different materials have different molecular structures and densities, which affect how light travels through them. For example, the refractive index of vacuum is 1, while it is higher for water and glass due to their molecular arrangements.

3. **Temperature**:
- The refractive index also depends on temperature. As temperature increases, materials generally expand, causing their density to decrease. This change in density affects the speed of light in the medium, thereby altering the refractive index.

4. **Wavelength**:
- The refractive index is also a function of the wavelength of light. Different wavelengths of light travel at different speeds in a medium, leading to variations in the refractive index. This phenomenon is known as dispersion.

5. **Density**:
- Density of the material affects the refractive index as well. A denser medium typically slows down the speed of light more than a less dense medium, resulting in a higher refractive index.

6. **Conclusion**:
- Therefore, the absolute refractive index of a material depends on:
- Nature of the material
- Temperature
- Wavelength of light
- Density of the material

7. **Final Answer**:
- The most comprehensive answer that includes all dependencies is: **Nature of material, temperature, and wavelength**.