10 PHYSICS REVISION, CHAPTERS 21,22.
CHAPTER 21.
1. LAW OF REFLECTION : i = r (i = angle of incidence, r = angle of reflection)
normal
incident ray reflected ray
i r
2. Specular reflection : where reflecting surface is perfectly smooth.
Regular surfaces give rise to ______reflections.
3. Draw diagram 21.4 (a.) and (b.)
PLANE MIRRORS
4. A plane mirror is a ______mirror.
5. The image of an object is the same ______behind the mirror as the object is in front of the mirror. The image seen in a plane mirror is always a ______or ______image.
6. Do questions 1 to 7.
7. Copy diagram 21.6
PA is called the ______of the mirror.
Copy diagram 21.7 (a.) Concave, and (b.) Convex.
8. The point to which the light from a distant object is reflected by a concave mirror is called the ______or ______.
9. Copy figure 21.8.
A ray parallel to a principal axis is reflected through the ______point.
10. The distance FB is called the ______length. f = ______, where R is the ______of curvature.
11. (a.) A ray ______to the mirror axis is reflected through the focus.
(b.) A ray ______the focus is reflected parallel to the mirror axis.
(c.) A ray through the centre of curvature is ______.
REAL IMAGE. (MIRROR)
12. Copy figure 21.10
When an object is placed outside the focal point F of a concave mirror a ______image is formed.
Copy figure 21.11
When an object is placed inside the focal point a ______image is formed.
*MIRROR EQUATION.
13. Used to find the location of an image.
do is the ______distance.
di is the ______distance.
O is the ______height.
I is the ______height.
14. O = do
I di
15. MIRROR EQUATION is : 1 + 1 = 1
do di f
f is the ______length of the mirror.
16. M is the magnification = I = di
O do
17. Do questions 8 to 11.
18. CONVEX MIRRORS.
Copy figure 21.13.
(a.) Incident rays parallel to the mirror axis are reflected as though they came from the ______point.
(b.) An incident ray heading towards the focal point is reflected parallel to the ______.
(c.) A ray heading towards the centre of curvature is reflected back on itself.
19. Copy figure 21.14 and 21.15 and the 3 points outlined on p497.
20. Do questions 16 to 22.
* SNELL’S LAW.
21. Copy figure 21.16.
n is called the index of refraction.
n = c = speed of light in a vacuum
v speed of light in a material
22. SNELL’S LAW : n1sin1 = n2sin2
n1 is the refractive index of incident material, n2 is the refractive index of the refracting medium, 1 is the angle of incidence, 2 is the angle of refraction.
23. Copy figure 21.18 (a.) and (b.).
24. Do questions 23 to 31.
25. TOTAL INTERNAL REFLECTION.
Copy figure 21.21
c is called the ______angle.
When i (incident angle) is greater than c total internal reflection occurs
1 = c : n1sinc = n2sin900
sin c = n2
n1
Typical critical angles are ____ for water, _____ for glass and ___ for diamond.
26. Do questions 34 to 37.
* LENSES.
27. Copy figures 21.23 (a.), (b.) without the wavefronts.
28. The distance from the centre of a lens to the focal point is called the ______length (f).
29. Copy, along with descriptions in red, figures 21.25, 21.27 and 21.28. (read fig.21.26)
30 For lenses :
1 + 1 = 1
do di f
31. * Points 1,2,3 on p511, copy these and read carefully.
32. Questions 38 to 50.
33. Do not do section 21.12.