This document discusses types of lenses and ray diagrams. It describes converging lenses which bring light rays to a focus at a focal point. Convex lenses are converging lenses that have a focal length and form different types of images - magnified/diminished, real/virtual - depending on the object distance relative to the focal length. Examples given include magnifying glasses, spotlights, projectors, photocopiers, cameras, telescopes.

1. CONVERGING LENSES SECONDARY 3 PHYSICS

2. Types of Lenses Convex Lens (converging) Concave Lens (diverging)

3. Converging Lenses Focal length Principal focus or Focal point Optical centre Focal plane Principal axis

4. Ray Diagrams F F

5. Images Formed by Lens Magnifying glass upright, magnified, virtual u < f Spotlight upright, magnified, virtual u = f Projector Inverted, magnified, real f < u < 2f Photocopier Inverted, same size, real u = 2f Camera, eye Inverted, diminished, real u > 2f Telescope Inverted, diminished, real u =  Uses Type of image Object distance