1. What is meant by the law of reflection?
2. If you look at yourself in a bathroom mirror and are 15 cm away from the mirror, how far away will your image be?
3. If you look at your image in a bathroom mirror and see your image 50 cm away, how far are you from the mirror?

18.2 Reflection from a Curved Mirror

4. Is the inside of a shiny spoon a convex or a concave mirror? What is the outside of a shiny spoon?
5. Why is the bulb in a spotlight located very near the focal point of a reflecting mirror?

18.3 Images Formed by Curved Mirrors

6. A make-up mirror or a shaving mirror is used to provide an enlarged image of your face. Is this a concave mirror or a convex mirror? Will such a mirror always provide an enlarged image?
7. Thinking of the principal rays, if a ray of light comes into a concave mirror parallel to the optic axis, what happens to it after it is reflected?

18.4 Apparent Depth

8. If you are aiming at a fish, should you aim above or below where you see the fish

18.5 Lenses

9. What do we call a lens that is thicker in the middle and thinner at the edges?
10. What do we call a lens that is thinner in the middle and thicker at the edges?

18.6 Images Formed by Lenses

11. Thinking of the principal rays, if a ray of light comes into the very center of a lens, how does its direction after it leaves the lens compare to its incoming direction?
12. What kind of images can be produced by a converging lens? Can a converging lens produce both real and virtual images? Can it produce images that are smaller or larger than the object? Give examples.
13. What kind of images can be produced by a diverging lens? Can a diverging lens produce both real and virtual images? Can it produce images that are smaller or larger than the object? Give examples.

18.7 Aberration

14. What is the difference between chromatic aberration and spherical aberration?
15. Is chromatic aberration of any concern if you use a lens only to take black and white photographs?
16. Why do large astronomical telescopes us parabolic mirrors instead of spherical mirrors?
17. Why do expensive, high-quality, large-aperature photographic lenses use "non-spheric" or "aspheric" lenses?