Sunday, 27 October 2013

CBSE Class 10 - Science - Ch 11 - The Human Eye and the Colourful World (MCQs)

The Human Eye and the Colourful World
CBSE Class 10 - Physics - CH11: The Human Eye and the Colourful World (NCERT Q & A)
Dispersion of Light
Which light bends the most?

Q1: By which optical phenomenon, the splitting of white light into seven constituent colours occur?
(a) Refraction
(b) Reflection
(c) Dispersion
(d) Interference

Q2: A human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This phenomenon is due to:

(a) near sightedness
(b) long sightedness
(c) accomodation
(d) persistence of vision

*Q3: Which of the following are the primary colours?
(a) Red, Blue, Yellow
(b) Red, Green, Violet.
(c) Yellow, Green Blue
(d) Red, Green, Blue

Q4(NCERT): The human eye forms the image of an object at its
(a) cornea
(b) iris
(c) pupil
(d) retina

Q5(NCERT): The least distance of distinct vision for a young adult with normal vision is about
(a) 25 m
(b) 2.5 cm
(c) 25 cm
(d) 2.5 m

Q6: A person cannot see objects clearly beyond 50 cm. The power of lens to correct the vision is:

(a) +5 D
(b) -0.5 D
(c) -2 D
(d) +2 D

Q7: Which phenomenon is responsible for the twinkling of stars?
(a) Atmosphere reflection
(b) Atmosphere refraction
(c) Reflection
(d) Total internal reflection

Q8(NCERT): The change in focal length of an eye lens is caused by the action of the
(a) pupil
(b) retina
(c) ciliary muscles
(d) iris

Q9: What is the time difference between actual sunset and apparent sunset?
(a) 2 s
(b) 20 s
(c) 2 minute
(d) 20 minute

Q10: When light passes through a prism, the colour which deviates the least is:

(a) red
(b) blue
(c) violet
(d) green

Q11: Which of the following optical phenomenon is used in cinematography or movie projectors?

(a) accomodation
(b) persistence of vision
(c) interference
(d) short sightedness

1: (c) Dispersion
2: (c) accomodation
3: (a) Red, Blue, Yellow  option for Painting perspective (option is correct (d) Red, Green, Blue for Computer Graphics)
4: (d) retina
5: (c) 25 cm
6: (c) -2 D
7: (b) Atmosphere refraction
8: (c) ciliary muscles
9: (c) 2 minute
10: (a) red
11: (b) persistence of vision


  1. the third answer is the wrong one its option (a).
    thank you

    1. Thanks Megha for the correction. Answer is updated now.

    2. no its correct a and d both are correct

  2. no third should be red ,blue,and green .these are only the primary colours

    1. Sorry BT these Colors are primary of only for computer graphics.... n for light primary Colors are red,blue,yellow....So the correct option is (a)


  3. Myopia is also known as near-sightedness. A person with myopia can see nearby objects clearly but cannot see distant objects distinctly. In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself. This defect may arise due to

    excessive curvature of the eye lens, or
    elongation of the eyeball.

  4. Light coming from the stars undergoes refraction on entering the Earth’s atmosphere. This refraction
    continues until it reaches the Earth’s surface. This happens because of uneven heating of atmospheric
    air. Hence, the atmospheric air has changing refractive index at various altitudes. In this case,
    starlight continuously travels from a rarer medium to a denser medium. Hence, it continuously bends
    towards the normal

    so atmosphere refraction is responsible for twinkling the star

  5. I'm still having doubt about the 3rd que. What if they will ask the same que. In board? Which answer we have to write. Please reply me fast on :


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