Surfaces which cause diffuse reflection

Options

A. Plane mirror
B. Still water in a lake
C. Clean, polished steel plate
D. Wooden bark of a tree

Answer

### Step-by-Step Solution:

1. **Understanding Diffuse Reflection**:
- Diffuse reflection, also known as irregular reflection, occurs when light rays strike a rough surface and scatter in various directions. This is different from regular reflection, where light rays reflect at the same angle they hit a smooth surface.

2. **Identifying Surface Characteristics**:
- To determine which surfaces cause diffuse reflection, we need to identify surfaces that are not smooth. Smooth surfaces, like mirrors, reflect light in a uniform direction, while rough surfaces scatter light.

3. **Analyzing Given Surfaces**:
- **Plain Mirror**: A plain mirror has a smooth surface and reflects light uniformly. Therefore, it does not cause diffuse reflection.
- **Still Water in a Lake**: If the water is completely still, it acts like a smooth surface and will reflect light regularly, not diffusely.
- **Clean Polished Steel Plate**: Similar to the mirror, a polished steel plate is smooth and will reflect light in a uniform manner, not causing diffuse reflection.
- **Wooden Bark of a Tree**: The bark of a tree is rough and uneven, which allows light to scatter in different directions, making it capable of causing diffuse reflection.

4. **Conclusion**:
- Among the surfaces analyzed, the only one that can cause diffuse reflection is the wooden bark of a tree. Therefore, the correct answer is the wooden bark of a tree.

### Final Answer:
The surfaces which cause diffuse reflection include the **wooden bark of a tree**.

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