Which of the following is true about the value of refractive index of quartz glass ?

Options

A. Same in all directions
B. Different in different directions
C. Cannot be measured
D. Always zero

Explanation

To determine which statement is true about the refractive index of quartz glass, we can analyze the properties of quartz glass and its refractive index.

### Step-by-Step Solution:

1. **Understanding Quartz Glass**:
- Quartz glass is a type of glass made primarily from silicon dioxide (SiO2). It is known for its clarity and high resistance to thermal shock.

2. **Properties of Quartz Glass**:
- Quartz glass is classified as an amorphous solid, meaning it lacks a long-range ordered structure that is characteristic of crystalline solids.

3. **Isotropic Nature**:
- Amorphous solids, including quartz glass, exhibit isotropy. This means that their physical properties, such as refractive index, are the same in all directions.

4. **Refractive Index**:
- The refractive index of a material is a measure of how much the speed of light is reduced inside the material compared to the speed of light in a vacuum. For quartz glass, this value is consistent in all directions due to its isotropic nature.

5. **Conclusion**:
- Since quartz glass is isotropic, the refractive index is the same in all directions. Therefore, the correct statement about the refractive index of quartz glass is that it is the same in all directions.

### Final Answer:
The value of the refractive index of quartz glass is the same in all directions.