Polarisation can be produced by

Options

A. reflection
B. double refraction
C. scattering
D. all of the above

Answer

To solve the question "Polarisation can be produced by", we will analyze the different methods by which polarization occurs.

### Step-by-Step Solution:

1. **Understanding Polarization**:
- Polarization refers to the process of confining the oscillation of light waves to a particular direction or plane. This means that instead of light waves oscillating in all directions, they are restricted to a single plane.

2. **Methods of Polarization**:
- **Reflection**: When light reflects off a surface, particularly at a certain angle (Brewster's angle), the reflected light can become polarized. This is commonly observed with light reflecting off water or glass surfaces.

- **Double Refraction**: Certain materials, known as birefringent materials (like calcite), split incoming light into two rays, each polarized in different directions. This phenomenon is known as double refraction.

- **Scattering**: When light interacts with small particles in the atmosphere, it can scatter in different directions. The scattered light can become polarized, especially when observed at certain angles relative to the light source.

3. **Conclusion**:
- Since polarization can occur through reflection, double refraction, and scattering, the correct answer to the question is "all of them".

### Final Answer:
Polarisation can be produced by reflection, double refraction, scattering, and thus the answer is "all of them".

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