Human Eye and Colourful World
Class 10th Science Chapter MCQs
Human Eye and Colourful World Class 10 MCQs Questions
1.
A person cannot see distinctly objects kept beyond 2 m. This
defect can be corrected by using lens of power
(a) +0.5 D
(b) -0.5 D
(c) +0.2 D
(d) -0.2 D
Answer
Answer: (b) -0.5 D
2.
A student sitting on the last bench can read the letters
written on the blackboard but is not able to read / the letters written in his
textbook. Which of the following statements is correct?
(a) The near point of
his eyes has receded away.
(b) The near point of his eyes has come closer to
him.
(c) The far point of his eyes has come closer to him.
(d) The far
point of his eyes has receded away.
Answer
Answer: (a) The near point of his eyes has receded away.
3.
What type of image is formed by the eye lens on the
retina?
(a) Real and erect
(b) Virtual and inverted
(c) Real and
inverted
(d) Virtual and erect
Answer
(c) Real and inverted
4.
The amount of light entering the eye can be controlled by
the
(a) iris
(b) pupil
(c) cornea
(d) ciliary
muscles
Answer
(b) pupil
5.
At noon, the Sun appears white as
(a) blue colour is
scattered the most
(b) red colour is scattered the most
(c) light is least
scattered
(d) all the colours of the white light are scattered
away
Answer
(c) light is least scattered
6.
Twinkling of stars is due to
(a) reflection of light by
clouds
(b) scattering of light by dust particles
(c) dispersion of light
by water drops
(d) atmospheric refraction of
starlight
Answer
(d) atmospheric refraction of starlight
7.
The splitting of white light into different colours on passing
through a prism is called
(a) reflection
(b) refraction
(c)
dispersion
(d) deviation
Answer
(c) dispersion
8.
A person cannot see distinctly objects kept beyond 2 m. This
defect can be corrected by using a lens of power
(a) + 0.5 D
(b) – 0.5
D
(c) + 0.2 D
(d) – 0.2 D
Answer
(b) – 0.5 D
9.
The clear sky appears blue because
(a) blue light gets
absorbed in the atmosphere.
(b) ultraviolet radiations are absorbed in the
atmosphere.
(c) violet and blue lights get scattered more than lights of all
other colours by the atmosphere.
(d) light of all other colours is scattered
more than the violet and blue colour lights by the
atmosphere.
Answer
(c) violet and blue lights get scattered more than lights of all other colours by the atmosphere.
10.
One cannot see through the fog, because
(a) refractive
index of the fog is very high
(b) light suffers total reflection at
droplets
(c) fog absorbs light
(d) light is scattered by the
droplets
Answer
(d) light is scattered by the droplets
11.
Refraction of light by the earth’s atmosphere due to
variation in air density is called
(a) atmospheric reflection
(b)
atmospheric dispersion
(c) atmospheric scattering
(d) atmospheric
refraction
Answer
(d) atmospheric refraction
12.
The deflection of light by minute particles and molecules of
the atmosphere in all direction is called …………………….. of light.
(a)
dispersion
(b) scattering
(c) interference
(d) tyndell
effect
Answer
(c) interference
13.
The air layer of atmosphere whose temperature is less then
the hot layer behave as optically
(a) denser medium
(b) rarer medium
(c) inactive medium
(d) either denser or rarer
medium
Answer
(a) denser medium
14.
The focal length of the eye lens increases when eye
muscles.
(a) are relaxed and lens becomes thinner
(b) contract and lens
becomes thicker
(c) are relaxed and lens becomes thicker
(d) Contract and
lens becomes thinner.
Answer
(a) are relaxed and lens becomes thinner
15.
The colour that is scattered the least by the tiny particles
and the atoms/ molecules of the atmosphere is
(a) Violet
(b) Green
(c)
yellow
(d) Red
Answer
(d) Red
16.
The image formed on the retina of the human eye is
(a)
virtual and inverted
(b) real and inverted
(c) real and erect
(d)
virtual and erect
Answer
(b) real and inverted
17.
When a person is myopic, he/ she can clearly see
(a) both
nearby and far off objects
(b) Only nearby objects
(c) only far off
objects
(d) Neither nearby nor far off objects
Answer
(b) Only nearby objects
18.
The defect of vision in which the person is able to see
distant object distinctly but cannot see nearby objects clearly is called
(a)
Long-sightedness
(b) Far-sightedness
(c) Hypermetropia
(d) All of the
above
Answer
(d) All of the above
19.
The defect of myopia can be corrected by using
(a) Concave
lens
(b) Convex lens
(c) Either concave or convex
(d) A complicated
combination of lenses.
Answer
(a) Concave lens
20.
Which of the following phenomenon contributes significantly
to the reddish appearance of the sun at sunrise or sunset?
(a) Dispersion of
light
(b) Scattering of light
(c) Total internal Reflection
(d)
Reflection of light from the earth
Answer
(b) Scattering of light
21.
Assertion: Concave mirrors are used as reflectors in torches,
vehicle head-lights and in search lights.
Reason: When an object is placed
beyond the centre of curvature of a concave mirror, the image formed is real and
inverted.
(a) Both A and R are true and R is the correct explanation of
A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and
R are false.
Answer
(b) Both A and R are true but R is not the correct explanation of A.
22.
Assertion: The near-point of a hypermetropic eye is more than
25 cm away.
Reason: Hypermetropia is corrected using spectacles containing
concave lenses.
(a) Both A and R are true and R is the correct explanation of
A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
(e) Both A and
R are false.
Answer
(c) A is true but R is false.
23.
Which of the following is a natural phenomenon which is
caused by the dispersion of sunlight in the sky?
(a) Twinkling of stars
(b) Stars seem higher than they actually are
(c) Advanced sunrise and delayed
sunset
(d) Rainbow
Answer
(d) Rainbow
24.
The medical condition in which the lens of the eye of a
person becomes progressively cloudy resulting in blurred vision is called
(a)
myopia
(b) hypermetropia
(c) presbyopia
(d)
cataract
Answer
(d) cataract
25.
The least distance of distinct vision for a normal eye is
(a) infinity
(b) 25 cm
(c) 2.5 cm
(d) 25 m
Answer
(b) 25 cm
26.
The defect of vision in which a person cannot see the distant
objects clearly but can see nearby objects clearly is called
(a) myopia
(b) hypermetropia
(c) presbyopia
(d) bifocal
eye
Answer
(a) myopia
27.
A person cannot see distinctly objects kept beyond 2 m. This
defect can be corrected by using a lens of power
(a) + 0.5 D
(b) – 0.5
D
(c) + 0.2 D
(d) – 0.2 D
Answer
(b) -0.5 D
28.
Near and far points of a young person normal eye respectively
are
(a) 0 and infinity
(b) 0 and 25 cm
(c) 25 cm and infinity
(d) 25
cm and 150 cm.
Answer
(c) 25 cm and infinity
29.
Twinkling of stars is due to atmospheric
(a) dispersion of
light by water droplets
(b) refraction of light by different layers of
varying refractive indices
(c) scattering of light by dust particles
(d)
internal reflection of light by clouds.
Answer
(b) refraction of light by different layers of varying refractive indices
30.
The danger signals installed at the top of tall buildings are
red in colour. These can be easily seen from a distance because among all other
colours, the red light
(a) is scattered the most by smoke or fog
(b) is
scattered the least by smoke or fog
(b) is absorbed the most by smoke or
fog
(c) moves fastest in air
Answer
(b) is scattered the least by smoke or fog
31.
When white light enters a prism, it gets split into its
constituent colours. This is due to
(a) different refractive index for
different wavelength of each colour
(b) each colours has same velocity in the
prism.
(c) prism material have high density.
(d) Scattering of
light
Answer
(a) different refractive index for different wavelength of each colour
32.
The change in focal length of an eye lens is caused by the
action of the
(a) Pupil
(b) Retina
(c) Cilliary muscles
(d)
Iris
Answer
(c) Cilliary muscles
33.
The human eye forms the image of an object at its
(a)
Cornea
(b) Iris
(c) Pupil
(d) Retina
Answer
(d) Retina
34.
The least distance of distinct vision for an eye lens is
caused by the action of the
(a) 25 m
(b) 2.5 cm
(c) 25 cm
(d) 2.5
m
Answer
(c) 25 cm
35.
The human eye can focus objects at different distances by
adjusting the focal length of the eye lens. This is due to
(a) Presbyopia
(b) Accommodation
(c) Near-sightedness
(d)
Far-sightedness
Answer
(b) Accommodation
36.
Bi-focal lens are required to correct
(a) astigmatism
(b) coma
(c) myopia
(d) presbyopia
Answer
(d) presbyopia
37.
The ability of eye lens to adjust its focal length to form a
sharp image of the object at varying distances on the retina is called
(a)
Power of observation of the eye
(b) Power of adjustment of the eye
(c)
Power of accommodation of the eye
(d) Power of enabling of the
eye
Answer
(c) Power of accommodation of the eye
38.
Myopia and hypermetropia can be corrected by
(a) Concave
and plano-convex lens
(b) Concave and convex lens
(c) Convex and concave
lens
(d) Plano-concave lens for both defects.
Answer
(b) Concave and convex lens
39.
The muscular diaphragm that controls the size of the pupil
is
(a) cornea
(b) ciliary muscles
(c) iris
(d)
retina
Answer
(c) iris
40.
The black opening between the aqueous humour and the lens is
called
(a) retina
(b) iris
(c) cornea
(d)
pupil
Answer
(d) pupil
41.
A prism ABC (with BC as base) is placed in different
orientations. A narrow beam of white light is incident on the prism as shown in
the Figures given below. In which of the following cases, after dispersion, the
third colour from the top corresponds to the colour of the sky?
(a) (i)
(b) (ii)
(c) (iii)
(d) (iv)
Answer
Answer: (b) (ii)
42.
At noon the sun appears white as
(a) light is least
scattered.
(b) all the colours of the white light are scattered away.
(c)
blue colour is scattered the most.
(d) red colour is scattered the
most.
Answer
Answer: (a) light is least scattered.
43.
Which of the following phenomena of light are involved in the
formation of a rainbow?
(a) Reflection, refraction and dispersion
(b)
Refraction, dispersion and total internal reflection
(c) Refraction,
dispersion and internal reflection
(d) Dispersion, scattering and total
internal reflection
Answer
Answer: (c) Refraction, dispersion and internal reflection
44.
Twinkling of stars is due to atmospheric
(a) dispersion of
light by water droplets
(b) refraction of light by different layers of
varying refractive indices
(c) scattering of light by dust particles
(d)
internal reflection of light by clouds
Answer
Answer: (b) refraction of light by different layers of varying refractive indices
45.
The clear sky appears blue because
(а) blue light gets
absorbed in the atmosphere.
(b) ultraviolet radiations are absorbed in the
atmosphere.
(c) violet and blue lights get scattered more than lights of all
other colours by the atmosphere.
(d) light of all other colours is scattered
more than the violet and blue colour lights by the
atmosphere.
Answer
Answer: (c) violet and blue lights get scattered more than lights of all other colours by the atmosphere.
46.
Which of the following statements is correct regarding the
propagation of light of different colours of white light in air?
(a) Red
light moves fastest.
(b) Blue light moves faster than green light.
(c) All
the colours of the white light move with the same speed.
(d) Yellow light
moves with the mean speed as that of the red and the violet
light.
Answer
Answer: (c) All the colours of the white light move with the same speed.
47.
The danger signals installed at the top of tall buildings are
red in colour. These can be easily seen from a distance because among all other
colours, the red light
(a) is scattered the most by smoke or fog.
(b) is
scattered the least by smoke or fog.
(c) is absorbed the most by smoke or
fog.
(d) moves fastest in air.
Answer
Answer: (b) is scattered the least by smoke or fog.
48.
Which of the following phenomena contributes significantly to
the reddish appearance of the sun at sunrise or sunset?
(a) Dispersion of
light
(b) Scattering of light
(c) Total internal reflection of light
(d) Reflection of light from the earth
Answer
Answer: (b) Scattering of light
49.
The bluish colour of water in deep sea is due to
(a) the
presence of algae and other plants found in water
(b) reflection of sky in
water
(c) scattering of light
(d) absorption of light by the
sea
Answer
Answer: (c) scattering of light
50.
When light rays enter the eye, most of the refraction occurs
at the
(a) crystalline lens
(b) outer surface of the cornea
(c)
iris
(d) pupil
Answer
Answer: (b) outer surface of the cornea
51.
The focal length of the eye lens increases when eye
muscles
(a) are relaxed and lens becomes thinner
(b) contract and lens
becomes thicker
(c) are relaxed and lens becomes thicker
(d) contract and
lens becomes thinner
Answer
Answer: (a) are relaxed and lens becomes thinner
52.
Which of the following statement is correct?
(a) A person
with myopia can see distant objects clearly.
(b) A person with hypermetropia
can see nearby objects clearly.
(c) A person with myopia can see nearby
objects clearly.
(d) A person with hypermetropia cannot see distant objects
clearly.
Answer
Answer: (c) A person with myopia can see nearby objects clearly.
53.
A student traces the path of a ray through a glass prism for
four different values of angle of incidence. On analysing the diagrams he is
likely to conclude that the emergent ray
(a) is always parallel to the
incident ray.
(b) is always perpendicular to the incident ray.
(c) is
always parallel to the refracted ray.
(d) always bends at an angle to the
direction of incident ray.
Answer
Answer: (d) always bends at an angle to the direction of incident ray.
54.
A student is observing the diagram showing the path of a ray
of light passing through a glass prism. He would find that for all angles of
incidence the ray of light bends:
(а) towards the normal while entering into
the prism and away from the normal while emerging out of the prism
(b) away
from the normal while entering into the prism and towards the normal while
emerging out of the prism.
(c) away from the normal while entering as well as
while emerging out of the prism.
(d) towards the normal while entering as
well as while emerging out of the prism.
Answer
Answer: (а) towards the normal while entering into the prism and away from the normal while emerging out of the prism
55.
In the following diagram, the path of a ray of light passing
through a glass prism is shown:
In this diagram the angle of incidence, the angle of emergence and the angle of
deviation respectively are (select the correct option):
(a) X, R and T
(b)
Y, Q and T
(c) X, Q and P
(d) Y, Q and P
Answer
Answer: (d) Y, Q and P
56.
After tracing the path of a ray of light through a glass
prism a student marked the angle of incidence (∠i), angle of refraction (∠r),
angle of emergence (∠e) and the angle of deviation (∠D) as shown in the diagram.
The correctly marked angles are:
(a) ∠i and ∠r
(b) ∠i and ∠e
(c) ∠i, ∠e and ∠D
(d) ∠i, ∠r and
∠e
Answer
Answer: (b) ∠i and ∠e
57.
The splitting of white light into its component colours is
called
(a) refraction
(b) reflation
(c) dispersion
(d) tyndall
effect
Answer
Answer: (c) dispersion
58.
Reason behind advance sunrise and delayed sunset
(a)
atmospheric refraction
(b) total internal reflection
(c) dispersion
(d)
reflection
Answer
Answer: (a) atmospheric refraction
59.
Type of lens used in correction of myopia
(a) convex
lens
(b) concave lens
(c) reflecting lens
(d) bifocal
lens
Answer
Answer: (b) concave lens
60.
Type of lens used in correction of hypermetropia
(a)
concave lens
(b) reflecting lens
(c) bifocal lens
(d) convex
lens
Answer
Answer: (d) convex lens
61.
Myopia may arise due to
(a) excessive curvature of the eye
lens
(b) elongation of the eyeball
(c) both (a) and (b)
(d) none of
these
Answer
Answer: (c) both (a) and (b)
62.
In an experiment to trace the path of a ray of light through
a glass prism for different values of angle of incidence a student would find
that the emergent ray:
(a) is parallel to the incident ray
(b) is
perpendicular to the incident ray
(c) is parallel to the refracted ray
(d)
bends at an angle to the direction of incident ray
Answer
Answer: (d) bends at an angle to the direction of incident ray
63.
While performing the experiment to trace the path of a ray of
light passing through a glass prism, four students marked the incident ray and
the emergent ray in their diagrams in the manner shown below.
The correct path of the rays has been shown by:
(a) I
(b) II
(c)
III
(d) IV
Answer
Answer: (c) III
64.
A dark muscular membrane which controls size of pupil
(a)
eye
(b) iris
(c) cornea
(d) retina
Answer
Answer: (b) iris
65.
Least distance of distinct vision for normal eye is
(a) 25
cm
(b) 50 cm
(c) 75 cm
(d) infinity
Answer
Answer: (a) 25 cm
66.
Farthest point of a normal eye is
(a) 25 cm
(b) 50
cm
(c) 75 cm
(d) infinity
Answer
Answer: (d) infinity
67.
Crystalline lens of people at old age becomes milky and
cloudy. This condition is called
(a) myopia
(b) lever
(c) cataract
(d) presbyopia
Answer
Answer: (c) cataract
68.
The splitting of light into its component colours is
called
(a) Spectrum
(b) Dispersion
(c) Tyndall effect
(d)
Refraction
Answer
Answer: (b) Dispersion
69.
Bifocal lens is used in
(a) myopia
(b) lever
(c)
Cataract
(d) Presbyopia
Answer
Answer: (d) Presbyopia
70.
Stars appears to be twinkling because of
(a) atmospheric
refraction
(b) reflection
(c) Tyndall effect
(d)
spectrum
Answer
Answer: (a) atmospheric refraction