Evans SPH 3U1

Physics Grade 11

Unit 3: Light and Optics

Note 7: Lenses

 

Reference: Chapter 11.7

 

Similar to the study of mirrors, we will examine two types of lenses:

Converging Lens (Convex Shape)

Diverging Lens (Concave Shape)

 

The lenses are given their names by the way they refract light rays travelling through them.

 

Use Overheads: Definitions, Characteristics, Converging (then do pg. 394 #54 with class), Diverging (then do pg. 394 #55 with class), Thin Lens Equation

 

Remember:

Real Images  are formed at the point where the refracted rays cross (with lenses this is behind the lens, with mirrors this is in front of the  mirror)

Virtual Images are formed at the point where the refracted rays APPEAR to cross ( with lenses this is in front of the lens, with mirrors it is behind)

 

Converging lenses can produce both real and virtual images with varying sizes depending on the position of the object. Fig. 11.26 pg. 377

Diverging lenses produce only a smaller, virtual image.

 

Handout "Lens Diagram Practice Page"

Page 394 #54a, 55a, 57ac, 58a, 59, 6