A little something for my students...
Your boards are fast approaching and you have a weekend coming up, try out this question paper and submit it to me for correction.
HUMAN EYE AND THE COLOURFUL WORLD FM – 65 TIME – 1HR15MINS
MCQs (1x22= 22m)
1. When we enter a cinema hall, we cannot see properly for a
short time. This is because-
a) Pupil doesnt open b) Pupil does not close c) Adjustment of size of pupil takes some time d) None
a) Pupil doesnt open b) Pupil does not close c) Adjustment of size of pupil takes some time d) None
2. The property of persistence of vision is used in-
a) Short sightedness b) Long sightedness c) Cinematography d) Colour vision
3. Variable focal length of eye is responsible for-
a) Accommodation of eye b) Persistence of vision c) Colour blindness d) Least distance of distinct vision
a) Accommodation of eye b) Persistence of vision c) Colour blindness d) Least distance of distinct vision
4. A concave lens of suitable focal length is used for correcting a
a) Myopic eye b) Hypermetropic eye c) Both a and b d) nor a nor b
5. Splitting of white light into seven colours on passing through the glass prism is called
a) Reflection b) Refraction c) Scattering d) Dispersion
6. The broad wavelength range of visible spectrum is
a) 4000-8000A b) 2000-4000A c) 10000-20000A d) None of the above
7. For which colour, refractive index of glass is maximum? a) Red b) Violet c) Green d) Yellow
8. Which colour suffers least deviation on passing through a prism? a) Red b) Violet c) Indigo d) Blue
9. Blue colour of sky is due to a) Scattering b) Reflection c) Refraction d) Diffraction
10. Red colour of the sun at the time of sunrise and sunset is because-
a) Red colour is least scattered b) Blue colour is least scattered
c) Red colour is scattered the most d) All colours are equally scattered
11. A human eye can focus objects at different distances by adjusting the focal length of the eye lens. This is due to – (a)Persistence of vision (b)Near sightedness (c)Accommodation (d)Far sightedness
12. Cinematography makes use of (a) Accommodation (b) Persistence of vision (c) Least distance of distinct vision (d) Bi-focal lens system
13. Human eye forms the image of an object at its (a)Cornea (b) Pupil (c) Iris (d) Retina
14. The change of focal length of an eye lens to focus the image of objects at varying distances is done by the action of the - (a)Pupil (b)Retina (c)Ciliary muscles (d)Blind spot
15. The convex lens of focal length 20cm each are separated by a distance of 10cm for focal length of combination is :- (a) 20cm (b) 40cm (c) 30cm (d) 13.3cm
16. Two convex lenses of focal length 10cm and 20cm are kept in contact .The focal length of the combination is: (a) 20/3 cm (b) 40 cm (c) 12cm (d) 15 cm
17. Two lenses of power –1.75D and +2.75D are placed in
contact. The focal length of the combination is :-
(a)50cm (b)100cm (c) 75cm (d) 125cm
(a)50cm (b)100cm (c) 75cm (d) 125cm
18. A myopic person cannot see clearly:-
(a)Distant objects (b)Near objects (c)Near and distant objects (d)None of the above
19. A long-sighted person cannot see clearly:
(a)Near objects (b) Distant objects (c) Both distant and near objects (d) None
20. A person having Presbyopia should use:-
(a)Convex lens (b) Concave lens (c) Cylindrical lenses (d) Bifocal lenses
21. A person cannot see fundamental colours (red, blue, green). This defect is called
(a) Myopia (b) Presbyopia (c) Colour blindness (d) Astigmatic
22. The defect of astigmatism can be rectified by using
(a)Convex lens (b) Cylindrical lens (c) Concave lens (d ) Bifocal lens
Answer the following Questions:
1. With the help of a ray diagram, show the two most common defects of the eye(2)
Explain why it is caused(2) and draw and represent how it can be rectified (2)
2. Draw a neat labelled diagram to show the dispersion of light (1). Why do we see dispersion? (1)
3. When you enter a dark room from sunlight, you cannot see objects for some amount of time. Why does it happen? (2)
4.Why do we see the twinkling of stars, but the light of the planets appears stationary and resolute? (2)
5. What is the least distant of distinct vision for a normal human eye? Calculate the power at that case. (2)
6. Why do different colours deviate through different angles on passing through a prism? (1)
7. Which phenomenon is responsible for increasing the apparent length of the day by 4 minute? Explain the occurrence. (3)
8. What is the far point of a person suffering from Myopia? (1)
9. What name is given to front transparent part of human eye? (1)
10. Which kind of lens is an eye lens and what is the nature of image formed by our eye? (2)
11. Name the liquids present in the eye and state their location & function. (3)
12. Where does most of the refraction of light in an eye occurs? (1)
13. How is the amount of light entering the eye controlled? (1)
14. Define the term (1) Near point (2) Far point (1)
15. Why is a normal eye not able to see clearly the object closer than 25 cm. (1)
16. Draw a ray diagram to show the refraction of light through a glass prism on the diagram mark. (a) Incident ray (b) Emergent ray and (c) Angle of deviation (1.5)
17. How is the dispersed white light recomposed? (1)
18. The near point of a hypermetropic eye is at 75 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye. (2)
19. A 52-year-old near-sighted person wears eye glass with a power of -5.5D for distance viewing and +1.5D in the near vision of his bi-focal. What is the focal length of the i) distance viewing part ii) near viewing part (2)
20. What is spectrum? What are the types of spectrum, define each kind. (2)
21. What is the Angle of Prism? (1)
22.Why do we need two eyeballs? (1.5)
23. What is colour blindness? Is it curable? (1.5)
24. Differentiate between monochromatic and polychromatic light. Give examples of sources of such light. (1.5)
J BEST OF LUCK J
