The image formed by a plane mirror has several distinct properties, which can be considered the 'rules' or characteristics of how it is formed. These properties are consistent for any object placed in front of a plane mirror.
Key Characteristics of Image Formation by a Plane Mirror
Based on the principles of reflection and ray tracing, the image produced by a plane mirror always exhibits the following characteristics:
- Virtual Image: The image obtained is virtual. This means that the light rays do not actually converge at the location of the image; instead, they appear to diverge from that point behind the mirror. A virtual image cannot be projected onto a screen.
- Laterally Inverted: The image is laterally inverted. This is perhaps one of the most noticeable properties. It means that the image is reversed from left to right. For example, if you raise your right hand while looking in a plane mirror, your image will appear to raise its left hand. This is why the word "AMBULANCE" is often written backward on the front of the vehicle so that it appears correctly when viewed in a rearview mirror.
- Erect Image: The image is erect. An erect image means that it is upright relative to the object. If the object is standing up, the image will also appear standing up, not upside down.
- Same Size: The size of the image is the same as the size of the object. A plane mirror does not magnify or diminish the object; the image appears to be the exact same height and width as the original object.
- Equidistant from the Mirror: The distance between the image obtained from the mirror is the same as the distance between the object from the mirror. If an object is placed 1 meter in front of a plane mirror, its image will appear to be 1 meter behind the mirror. The total distance between the object and its image is therefore twice the distance of the object from the mirror.
Summarizing Image Properties
These characteristics can be neatly summarized:
| Property | Description |
|---|---|
| Type | Virtual |
| Orientation | Erect (Upright) |
| Lateral State | Laterally Inverted (Left-Right Reversed) |
| Size | Same size as the object |
| Distance | Same distance behind the mirror as the object is in front |
Understanding these properties is fundamental to comprehending how plane mirrors work and their applications, from everyday bathroom mirrors to periscopes.
