Multiple choice questions
1. When we enter a cinema hall, we cannot see properly for a short time. This is because-
a) Pupil does not open b) Pupil does not close
c) Adjustment of size of pupil takes some time d) None of these above Ans: (c)
2. The property of persistence of vision is used in-
a) Short sightedness b) Long sightedness c) Cinematography d) Colour vision Ans: (c)
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 Ans: (a)
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 Ans: (a)
5. Splitting of white light into seven colours on passing through the glass prism is called-
a) Reflection b) Refraction c) Scattering d) Dispersion Ans: (d)
6. The broad wavelength range of visible spectrum is-
a) 4000-8000A b) 2000-4000A
c) 10000-20000A d) None of the above Ans: (a)
7. For which colour, refractive index of glass is maximum?
a) Red b) Violet c) Green d) Yellow
Ans: (b)
8. Which colour suffers least deviation on passing through a prism?
a) Red b) Violet c) Indigo d) Blue
Ans: (a)
9. Blue colour of sky is due to-
a) Scattering of light b) Reflection of light c) Refraction of light d) Diffraction of light
Ans: (a)
10. Clouds appear red due to Rayleigh scattering. The statement is- a) True b) False
Ans: (b)
11. 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
Ans: (a)
12. 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 Ans: (c)
13. Cinematography makes use of - (a) Accommodation (b) Persistence of vision
(c) Least distance of distinct vision (d) Bi-focal lens system Ans: (b)
14. Human eye forms the image of an object at its –
(a)Cornea Pupil Iris Retina
Ans: (d)
15. 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 Ans: (c)
16. 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 Ans: (d)
17. 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 Ans: (a)
18. 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 Ans: (b)
19. Which eye piece satisfies the condition for spherical aberration:-
(a)Huygen’s eye piece (b)Ramsden’s eye piece (c)Both a and b (d)None of the above
Ans: (a)
20. A myopic person cannot see clearly:-
(a)Distant objects (b)Near objects (c)Near and distant objects (d)None of the above
Ans: (b)
21. A long-sighted person cannot see clearly:
(a)Near objects (b) Distant objects (c) Both distant and near objects (d) None
Ans: (a)
22. A person having Presbyopia should use:-
(a)Convex lens (b) Concave lens (c) Cylindrical lenses (d) Bifocal lenses Ans: (d)
23. A person cannot see fundamental colours (red, blue, green). This defect is called:-
(a) Myopia (b) Presbyopia (c) Colour blindness (d) Astigmatic Ans: (c)
24. The defect of astigmatism can be rectified by using: -
(a)Convex lens (b) Cylindrical lens (c) Concave lens (d ) Bifocal lens Ans: (b)
pl check the answer for the 20th question. I think the answer should be option 'a' (distant objects)
ReplyDeleteyup itz (a) distant objects #
ReplyDelete20A
ReplyDelete21 hypermetropia convex lens
ReplyDelete21 hypermetropia convex lens
ReplyDelete20A
ReplyDelete