II. HUMAN EYE AND THE COLOURFUL WORLD

II. HUMAN EYE AND THE COLOURFUL WORLD

1. What do you mean by accommodation of human eye?

2. Define power of accommodation of human eye and Calculate its value for a normal human eye.

3. Draw a neat labelled diagram of human eye and explain the function of each part.

4. What is Myopia? How is it caused? How can it be corrected? Explain with the help of a diagram.

5. What is hypermetropia? How is it caused? How can it be corrected? Explain with the help of a diagram.

6. What is presbiopia? How is it caused? How can it be corrected?

7. What is astigmatism? How can it be corrected?

8. What is dispersion?

9. Draw a neat diagram to show the dispersion of light when passed through a glass prism.

10. How is rainbow formed?

11. If you see a rainbow in the morning, in which direction of the sky will you see it?

12. What is scattering?

13. Explain the blue colour of sky?

14. Why clouds are white?

15. A red coloured piece of glass appears white when it is ground. Explain why?

16. What is Tyndal effect?

17. Write the constituent colours of white light in order of increasing wavelength.

18. When you enter a dark room from sunlight, you cannot see things for a while and after sometime you start seeing things. Explain this observation.

19. Why do stars twinkle?

20. Define near point and least distance of distinct vision. What is its value for a normal human eye?

21. Define far point. What is its value for a normal human eye?

22. Draw a neat labelled diagram showing the refraction of light through a glass prism.

23. The sun is seen a few minutes before actual sunrise and after actual sun set. Explain why?

24. The sky appears black when viewed from the surface of moon. Explain why?

25. Why danger signals are of Red colour?

26. Why sun appears reddish during sunrise and sunset?

27. The setting sun is more reddish than rising sun. Explain why?

28. What is persistence of vision? How does it help us in seeing motion pictures?

29. What are primary colors?

30. Why planets do not twinkle?

31. What is total internal reflection?

32. What is cataract? How is it corrected?