Imagine a mirror as a perfectly flat, shiny surface. When a light ray strikes it, the ray reflects back at an angle equal to the angle of incidence. This is the law of reflection:
\$\theta{\text{incidence}} = \theta{\text{reflection}}\$
Think of it like a ball bouncing off a wall: it comes back at the same angle it hit the wall. In a plane mirror, all rays that hit the surface follow this rule, creating a clear image.
1️⃣ Draw the real object in front of the mirror.
2️⃣ Extend the reflected rays backward (behind the mirror).
3️⃣ The intersection of these extended rays gives the position of the image.
Because the rays are only extended, the image is virtual – you cannot project it onto a screen.
Analogy: Imagine you are standing in front of a flat window. The people you see inside the window are like the virtual image – they appear behind the glass, but you can’t touch them. The same idea applies to a plane mirror.
| Property | What It Means |
|---|---|
| Size | Same as the object. |
| Distance from Mirror | Equal to the object’s distance. |
| Orientation | Same as the object (not inverted). |
| Real or Virtual | Virtual – cannot be projected. |
📌 Remember: For a plane mirror, the image is always virtual, upright, same size, and at the same distance behind the mirror as the object is in front.
📝 When answering:
💡 Quick Check: If you can’t project the image onto a screen, it’s virtual. If it looks the same size and orientation as the object, it’s a plane mirror image.
Put a small toy in front of a mirror and stand behind it. You’ll see the toy’s reflection behind the mirror. If you walk forward, the reflection moves backward at the same speed – that’s the virtual image moving with you!
👀 Try this at home and notice how the distance stays constant.