1. Lesson P4 Part 2 ~ Lenses & Refraction
UNIT 3 ~ PHYSICS
Lesson P4 Part 2 ~
Lenses & Refraction

2. Refraction & Lenses
When a light ray moves from air into a denser material, it bends towards the normal.
When a light ray moves from a denser material into air, it bends away from the normal.
A lens is a curved piece of material that refracts light to converge or diverge light rays.

3. Concave Lenses
Concave lenses are thinner in the middle than at the edges.
Light rays that pass through a concave
lens diverge.

4. Concave Lenses
Image is always smaller and upright no matter how far away from the lens it is.

6. Convex Lenses
Convex lenses are thicker in the middle than at the edges.
Light rays that pass through a convex lens converge.
The distance from the
focal point to the lens or
mirror is called the
focal length.

7. Convex Lenses
Size and orientation of the image depends on how far the object is from the lens.
More than 2 focal lengths smaller & inverted.
Between 1 & 2 focal lengths larger & inverted.
Object at focal length no image.
Less than one focal length larger & upright.