State which surface of a plane mirror reflects most of the light incident on it: the front smooth surface or the back silvered surface.

Answer

To determine which surface of a plane mirror reflects most of the light incident on it, we can analyze the properties of both surfaces of the mirror.

### Step-by-Step Solution:

1. **Understanding the Structure of a Plane Mirror**:
- A plane mirror typically consists of a glass sheet with a reflective coating (usually silver) applied to one side. The side with the reflective coating is known as the back silvered surface, while the opposite side is the front smooth surface.

2. **Identifying the Reflective Properties**:
- The back silvered surface is designed to reflect light. However, it is important to note that this surface may not be perfectly smooth and can absorb some light.
- The front smooth surface, being glass, is also capable of reflecting light, but its primary function is to allow light to pass through to some extent.

3. **Analyzing Reflection**:
- The smooth surface of the glass (the front surface) reflects light due to its smoothness, which allows for a clearer reflection.
- The back silvered surface, while it is coated to reflect light, may not reflect as efficiently as the smooth front surface because it can absorb some of the light.

4. **Conclusion**:
- Based on the properties of reflection, the front smooth surface of the plane mirror reflects most of the light incident on it compared to the back silvered surface.

### Final Answer:
The front smooth surface of a plane mirror reflects most of the light incident on it.