The synthetic material used for the preparation of polaroids prosses the propery of

Options

A. anomalous thermal expansion
B. optical activity
C. dichroism
D. none of the above

Answer

To solve the question regarding the property of synthetic materials used for the preparation of polaroids, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Polaroids**:
- Polaroids are optical devices that allow light waves of a specific polarization to pass through while blocking others. They are commonly used to produce linearly polarized light.

2. **Material Properties**:
- The synthetic materials used for making polaroids, such as certain plastics or crystals, must have specific optical properties that allow them to manipulate light.

3. **Selective Absorption**:
- The key property that these materials possess is called **selective absorption** or **dichroism**. This means that the material can absorb light waves depending on their polarization direction.

4. **Mechanism of Polarization**:
- When unpolarized light (which contains waves vibrating in multiple directions) strikes the polaroid, the material absorbs the light waves that are aligned with a certain direction (the absorption axis) more than those that are perpendicular to it.

5. **Resulting Polarized Light**:
- As a result of this selective absorption, the light that is transmitted through the polaroid becomes linearly polarized, with its electric field oscillating predominantly in one direction.

6. **Conclusion**:
- Therefore, the correct answer to the question is that the synthetic material used for the preparation of polaroids possesses the property of **selective absorption** or **dichroism**.

### Final Answer:
The synthetic material used for the preparation of polaroids possesses the property of selective absorption (dichroism).