1. What is rectilinear propagation of light?
2. What is the law of reflection?
3. What is the difference between regular and irregular reflection?
4. What is the focal length of a spherical mirror?
5. What is the difference between a real and virtual image?
6. What are the characteristics of an image formed by a convex mirror?
7. What is refraction of light?
8. What is total internal reflection?
9. What is refractive index?
10. What are the types of lenses?
11. What is the focal length of a lens?
12. What is the power of a lens?
13. What is the composition of white light?
14. What is dispersion of light?
15. What is atmospheric refraction?
16. What is scattering of light?
17. What is the structure of the human eye?
18. What is myopia?
19. What is hypermetropia?
20. What is presbyopia?