1. Refraction is the bending of light when passing from one medium to another. It occurs because the speed of light changes depending on the medium. 2. Convex lenses are thicker in the middle and cause light rays to converge, resulting in a real, inverted, and magnified image. Concave lenses are thinner in the middle and cause light rays to diverge, resulting in a virtual, upright, and minified image. 3. The focal length of a lens is the distance between the focal point and the center of the lens. Lens properties like image type, orientation, size, and position depend on the location of the object relative to the focal points and center of the lens.

1. REFRACTION
OF LIGHT

2. T E SUN RISE
H

3. T fish look
he
bigger

5. Why is the sun look bigger if it
is rising?
Why is fish look bigger in the
bottle?
Why is some thing look bigger
under the magnifying?

6. That it become, because :
Refraction
Of light

7. Allah berfirman di dalam Al
Qur’an : 24 ayat 39
Yang artinya :
Dan orang-orang yang kafir amalan-
amalan mereka laksana fatamorgana di
tanah yang datar yang disangka air oleh
orang yang dahaga, tapi bila didatanginya
air itu dia tidak mendapatinya sesuatu
apapun.

8. Refraction
Is The change direction or bending of
light at the inter face between two
transparent media.
It occur when the speed of light
changes
Look at the picture below !

9. Incident ray normal line
i
r
i = incident
•refracted ray angle is the angle between the
incidence ray and normal to the surface at the
incidence
• r = refracted angle is the angle between
the refracted and the same normal

10. Refraction is caused by :
The ray change speed.
normal
Incidence ray
air
Glass
refracted ray

11. normal
air
Glass

12. normal
y
ted ra
rac
ref
Glass
ay r air
nce
i de
I nc

13. normal
air
Glass

14. Note
The rays enter more optically dense medium where they
travel more slowly, the refracted rays bend toward the normal.
The angle of refraction is smaller than the angle of incidence
The rays passes from more optically dense medium
where they travel more quickly, the refracted rays bend away
from the normal.
The angle of refraction is bigger than the angle of incidence

15. Refraction is caused by :
The ray change speed.
The ratio of speed c of light in vacuum to the speed v of light
in medium is defined index of refraction (n)
C. vacuum
n = ------------
V. Medium

16. Table INDEX OF REFRACTION
Substance index of refraction
Gases
Air 1.000293
Carbon dioxide 1.00045
Liquids
Water 1.333
Ethyl alcohol 1.361
Solids
Ice 1.309
glass 1.6 – 1.9
Diamond 2.419

17. Resume
1. If rays enter to more optically dense medium
the refracted rays bend toward the normal
2. If rays exit from more optically dense medium
the refracted rays bend backward the normal
Look at the figure !

18. Incidence ray normal
refracted ray

19. normal
refracted ray
Incidence ray

20. Refracted ray in the PLANPARALEL
Refraction 1
Refraction 2
displacement ray

21. Refraction on the prism
Deviation angle

22. Multiple refraction

23. Total internal reflection
This phenomena can use to explain (light
propagating) fatamorgana
(light propagating) fatamorgana become
light exit from dense medium
(light propagating) fatamorgana become if
incidence angle more than critical angle
Critical angle is incidence angle that have
refracted angle of 90o

24. Inter face
Dense Medium
Ik
Total internal
reflection of light
Source light
Ik = critical angle is incidence angle that have refracted
angle of 90o

26. Like surface
of water
Air more dense
Surface of road

27. LENSES
Convex lenses (Magnifying
Lenses)
A glass which makes thing look bigger is use full in many
ways. Watch makers, scientists and people who cannot see
near
It is thicker in the middle than at the edges.
It can used to collect the rays of the sun on the spot,
and in this way burn a hole in piece of paper.
The spot where the sun’s ray collect is known focal
point.
The distance between the focal point and the lenses is
called focal length.
Lenses of different thickness have different focal length

28. LENSES
Concave lenses
It is thinner in the middle than
at the edges.
Parallel light rays which are
passing trough a concave lens
bend towards each other
(diverging.
In another word it is known
diverging lens.

29. Convex lens
Bikonveks konkaf konveks plan konveks

30. Concave lens
Bikonkaf konveks konkaf plan konkaf

31. Look at the figure
Principal axix

33. We can make smo o th in e dg e

34. Part of Convex lens
R1
Sumbu utama
x x x x
M 1 F1 O F2 M 2
R2
F1 dan F2 = Focal point
M1 dan M2 = Center of curve
O = center optic
R1 dan R2 = Radius of curve

35. Room of lens
II I IV
Sumbu utama
x x x x
M 1 F1 O F2 M 2
4 1 2 3

36. Drawing picture
M F O F M

37. We c a n c ha ng e a c o nve x le ns by
+
X x x x x
M 1 F1 O F2 M2

38. Dra wing p ic ture
Si
x x x x
M 1 So F1 O F2 M2
So = space of object (jarak benda)
Si = space of image (jarak bayangan)

39. Home work
Drawing picture if object on:
1. Room I
2. Room III
3. Focal point
4. Center of curve

40. Home Work
Complete the table below :
R.Objc R. Image Characteristic
I
II
III
IV

41. Perbesaran bayangan (M)
Perbesarann bayangan
dapat dirumuskan
M = [Si/So] = h’/h

42. +
X x x x x
O F2 M2
J benda berada di ruang tiga
ika
Sifat bayangan :
1. T erbalik
2. Diperkecil
3. nyata

43. +
X x x x x
O F2 M2
J benda berada di ruang satu
ika
Sifat bayangan :
1. T egak
2. Diperbesar
3. maya

44. +
X x x x x
O F2 M2
J benda berada di titik fokus
ika
Sifat bayangan : ?

45. +
X x x x x
O F2 M2
J benda berada di titik pusat kelengkungan
ika
Sifat bayangan : ?

46. Untuk m e m p e rm ud a h d a la m m e lukis
ba y a ng a n, le ns a c e kung d a p a t
d ig a m ba rka n s e p e rti ini
-
X x x x x
M 1 F1 O

47. Da la m m e lukis ba y a ng a n d ip e rluka n tig a
be rka s s ina r is tim e wa .
-
X x x x x
M 1 F1 O

48. M lukis ba y a ng a n p a d a le ns a c e kung
e
-
X x x x x
M 1 F1 O
Sifat bayangan :
1. T egak
2. Diperkecil
3. maya

49. M lukis ba y a ng a n p a d a le ns a c e kung
e
-
X x x x x
M 1 F1 O
Sifat bayangan :
1. T egak
2. Diperkecil
3. maya

50. Relation ship between so, si and f
1/ + 1/ = 1/
So Si f
So = jarak benda
Si = jarak bayangan
f = jarak fokus

51. Tugas di rumah !
Lengkapilah tabel berikut :
R.bd R. byg sifat
I
II
III
IV