1. The angle of vision of human beings is 60°. What apparatus are required to find this? Explain the factors observed by you with the help of a diagram.                   (AS 3) 4 Marks

2. Draw a neat diagram showing the formation of rainbow naturally in rainy season due to dispersion and total internal reflection of light. Explain giving reasons.        (AS 5) 4 Marks

3. Two friends, Kumar and Sridhar were playing in a garden. Suddenly Kumar observed seven colours in the sky. He showed it to his friend and asked him what was that beautiful formation. Then Sridhar explained him.
(i) What is the name of this natural phenomenon?
(ii) Which device can be used to obtain such a phenomenon?
(iii) Kumar was facing the colours then where was the sun at that time? Draw a diagram of dispersion of light by the rain drops.                                                                 (AS 4) 4 Marks

4. Think that lenses are not discovered. Imagine the consequences that are faced by a human suffering from eye defect. (AS 2) 2 Marks

5. Sea appears blue in colour. Guess the reasons for it.                                  (AS 2) 2 Marks

6. Why the danger signals are in red colour?

7. Predict in which shape the rainbow appear to a person travelling in aeroplane? (AS 2) 1 Mark

8. What do you mean by increase or decrease of sight?                                      (AS 1) 1 Mark

9. What happens when ciliary muscles become weak gradually?                      (AS 1) 1 Mark

10. What happens if the eye lens cannot adjust its focal lengths?                     (AS 1) 1 Mark

11. What are the limits of focal lengths of eye lens?                                             (AS 1) 1 Mark

12. Doctor advised to use a 2 D lens. Then what is the focal length of that lens? (AS 1) 1 Mark

13. An old man was unable to see both nearer as well as far off objects clearly. Then
(i) What was the defect of the old man?
(ii) Which lens can be used for clear vision of nearer and far off objects?       (AS 1) 2 Marks

14.
      

15.
   
(i) What is the defect of vision in the above diagram?
(ii) Draw a diagram showing the correction of eye defect with a lens.           (AS 5) 2 Marks