1. Curved Mirrors,
Ray Diagrams and
Nature of Image

2. Question:
How do we “see” things?

5. Iris and Pupil

7. Lens
The lens focuses the light that comes through, so we can see a clear image on the retina.

9. Eyes = “Light detectors”

12. How do mirrors work?

13. Eye sees image back here
Light from object reflects into eye

14. The coin appears to be here
True position of the coin

15. Lateral Inversion

16. Curved Mirrors
Concave (Converging) Mirror
Convex (Diverging) Mirror

17. Concave
(Converging)
Mirrors

18. Concave (Converging) Mirror
The mirror is “caved” in.
The light “converges” into the focus.

28. Concave Mirrors
Concave mirrors have a focal point in front of the mirror.
Concave mirrors focus (converge) light at the focal point. F

29. Convex (Diverging) Mirrors

30. Convex (Diverging) Mirrors

35. Convex Mirrors Convex mirrors have a focal point behind the mirror.
Convex mirrors spread (diverge) the light rays so that they appear to be coming from the focal point. F

36. Ray
Diagrams

37. P = pole , pa = principal axis F P r pa f
P = pole , pa = principal axis
C = centre of curvature r = radius of curvature
F = Focal point or focus f = focal length
f = r / 2

38. Drawing Ray diagrams – mirrors
Draw two rays from the top of the object – “parallel to focus” then “focus to parallel”
Find the point where the two reflected rays intersect – if they don’t, go backwards and draw dotted lines (the image is then virtual)

39. Concave Mirror – Case 1

40. Concave Mirror – Case 1

41. Concave Mirror – Case 1

42. Concave Mirror – Case 1

43. Concave Mirror – Cases 2 & 3

44. Concave Mirror – Case 4

45. Concave Mirror – Case 5

46. 1. 2. 3. 4. 5.

47. Concave (Converging) Mirror
Size
Orientation
Nature
Behind C
At C
Between C & F
At F
Between F & P

48. An image is virtual if cannot be projected onto a screen.
An image is real if it can be projected onto a screen (or a piece of paper).
An image is virtual if cannot be projected onto a screen.
Virtual Image

49. “Real Image”

50. “Virtual Image”

51. Concave (Converging) Mirror
Size
Orientation
Nature
Behind C
Diminished
Inverted
Real
At C
Same
Between C & F
Enlarged
At F
No image
Between F & P
Upright
Virtual

52. Convex Mirror

53. Convex Mirror

54. Convex Mirror

55. Convex Mirror

56. Concave (converging) mirrors
The image will be real and inverted if the object is located behind the focus.
The image will be virtual, upright and enlarged if the object is located between the mirror and the focus.
Convex (diverging) mirrors
Convex mirrors always produce virtual images which are always upright and smaller than the object.

57. Common mistakes No Arrowheads!!!! 
Solid lines instead of dashed lines, dashed lines instead of solid lines
Rays going through the mirror
Rays not hitting the mirror line

58. Drawing Ray diagrams – mirrors
Draw two rays from the top of the object – “parallel to focus” then “focus to parallel”
Find the point where the two reflected rays intersect – if they don’t, go backwards and draw dotted lines (the image is then virtual)