Overview
This lecture explains the difference between virtual and real images, focusing on how plane and concave mirrors form these images.
Plane Mirrors and Reflection
- A plane mirror has a flat, smooth reflecting surface.
- Light rays reflect off objects, then the mirror, and finally enter our eyes, letting us see an image.
- Reflection from plane mirrors follows the law of reflection.
- The rays reflected by the plane mirror diverge; extending them backward shows they appear to meet behind the mirror.
- The image appears to be behind the mirror, but no light actually reaches that point.
- Plane mirrors always form virtual images.
Virtual and Real Images
- A virtual image appears to come from a position behind the mirror but is not actually there.
- Virtual images are formed when reflected light rays diverge and do not really meet.
- A real image is formed when reflected light rays converge (meet) at a point.
- Real images always form on the same side of the mirror as the object.
- In real images, light rays actually reach the image location.
Spherical Concave Mirrors
- Concave mirrors are curved inward and are examples of spherical mirrors.
- Concave mirrors can form both real and virtual images, depending on the object's distance.
- Real images formed by concave mirrors are always inverted.
Key Terms & Definitions
- Plane Mirror — a mirror with a flat reflecting surface.
- Spherical Concave Mirror — a mirror with a reflecting surface curved inward.
- Virtual Image — an image that appears to form behind a mirror where light does not actually reach.
- Real Image — an image formed at a location where light rays converge and actually meet.
- Law of Reflection — the principle stating that the angle of incidence equals the angle of reflection.
Action Items / Next Steps
- Review characteristics of images formed by plane mirrors.
- Prepare to learn more about image formation by concave mirrors in future lessons.