Final answer:
Among the options provided, a plane mirror is the best reflector of light due to its smooth surface that reflects a significant amount of light that falls on it. Unlike a mirror, a plastic plate, wall, and paper have rough surfaces that scatter the light, making them less efficient at reflecting light.
Step-by-step explanation:
The best reflector of light among the options provided is a plane mirror. This is because a mirror's surface is highly smooth and capable of reflecting a significant amount of light that falls on it, often more than 90%. On the contrary, a plastic plate, wall, and paper have comparatively rough surfaces. When light falls on these surfaces, it is reflected in multiple directions because of the uneven surface, causing a diffused reflection. In contrast, rough surfaces like plastic plates, walls, and paper reflect light diffusely in many different directions, making it harder to see clear reflections. A plane mirror can reflect more than 90% of the light that falls on it, absorbing the rest, which makes it an efficient reflector.
Therefore, we can see these objects from various angles. However, their reflective efficiency is lower because they scatter the light instead of reflecting it in a specific direction, like a mirror. In short, the smoother the surface, the better it reflects light, which is why mirrors are used for tasks that require clear and precise reflections, such as grooming or driving.
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