The human eye and the colourful world Worksheet-2

The human eye and the colourful world Worksheet-2

11. Colour blind person may have

A. normal vision 

B. defective vision

C. sometimes normal and sometimes defective vision

D. cannot say

12. Focal length of eye lens is

A. fixed

B. variable

C. sometimes fixed and sometimes variable

D. cannot say

13. Variable focal length of eye lens is responsible for

A. accommodation of eye

B. persistence of vision

C. colour blindness

D. least distance of distinct vision

14. Far point of normal human eye is

A. 25 cm            B. 25 m              C. 500 m            D. infinity

15. Near point of normal human eye is

A. 25 cm            B. 25 mm           C. 25 m              D. not fixed

16. When ciliary muscles are relaxed, focal length of eye lens is

A. maximum 

B. minimum

C. neither maximum nor minimum

D. cannot say

17. A concave lens of suitable focal length is used for correcting a

A. myopic eye

B. hypermetropic eye

C. Myopic and hypermetropic eye

D. none

18. White light is made up of

A. seven colours                            B. six colours                      

C. all colours                                 D. no colour

19. Splitting of white light into seven colours on passing through a glass prism is called

A. Reflection                                  B. Refraction

C. Scattering                                  D. Dispersion

20. Which of the colours of visible light has minimum wavelength ?

A. violet              B. red                  C. yellow            D. green

Answer Key:

11. C

Explanation: Colour blindness is independent of the defects of vision.

12. B
13. A

Explanation: Accommodation of eye is due to variable focal length of eye lens.

14. D
15. A
16. A

Explanation: When ciliary muscles are relaxed, eye lens is thin and its focal length is maximum.

17. A
18. A
19. D
20. A

Explanation: Violet colour has least wavelength.