MCQExams
0:0:1
CBSE
JEE
NTSE
NEET
Practice
Homework
×
CBSE Questions for Class 10 Physics Human Eye And Colorful World Quiz 10 - MCQExams.com
CBSE
Class 10 Physics
Human Eye And Colorful World
Quiz 10
Which of the following adjustments are made by the eye to enable the clear vision of distant objects?
Report Question
0%
Relaxation of ciliary muscles
0%
Thinning of the eye lens
0%
Increasing the focal length
0%
All of the above
Explanation
The curvature of the eye lens can be modified to change its focal length to some extent by the ciliary muscles. When the muscles are relaxed, the curvature decreases making the lens thin and the focal length increase. This enables us to see distant objects clearly.
Match the following:
List I
List II
1
Myopia
a
Corrects far vision
2
Hypermetropia
b
Weakening of ciliary muscles
3
Presbyopia
c
Corrects near vision
4
Concave lens
d
Near sightedness
5
Convex lens
e
Far sightedness
Report Question
0%
1-b, 2-c, 3-a, 4-d, 5-e
0%
1-d, 2-e, 3-b, 4-a, 5-c
0%
1-a, 2-c, 3-e, 4-d, 5-b
0%
1-c, 2-e, 3-d, 4-b, 5-a
Explanation
Three common refractive defects of vision are myopia or near-sightedness, Hypermetropia or far-sightedness and Presbyopia. A person with myopia 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 can be corrected with the help of a concave lens of suitable power as it will bring the image back on to the retina. A person with hypermetropia cannot see nearby objects clearly. The near point is farther away from the 25 cm. This defect occurs because the image of the object is formed at a point behind the retina. This defect can be corrected by using a convex lens of appropriate power as it provides the additional focusing power required for forming the image at the retina. Presbyopia occurs due to decrease in the power of accommodation of the eye usually because of ageing which causes gradual weakening of the ciliary muscles and diminishes flexibility of the eye lens. Sometimes, a person may suffer from both myopia and hypermetropia. It can be corrected with the help of bifocal lenses.
Match the following
List I
List II
1
Aqueous humour
a
Forms inverted image on the retina
2
Vitreous humour
b
Spherical
3
Eyeball
c
Present between lens and retina
4
Crystalline lens
d
Present between lens and cornea
Report Question
0%
1-b, 2-c, 3-a, 4-d
0%
1-d, 2-c, 3-b, 4-a
0%
1-d, 2-a, 3-c, 4-b
0%
1-a, 2-d, 3-b, 4-c
Explanation
Aqueous humour is a transparent, gelatinous fluid similar to plasma. It is present between the lens and the cornea. Vitreous humour is also a clear gelatinous gel like fluid that fills the space between the lens and the retina. It helps in maintaining the shape of the retina by holding the retina in its place. The eyeball is approximately spherical in shape with a diameter of about 2.3 cm. The crystalline eye lens forms an inverted real image of the object on the retina, thus the correct matches are given in option $$B$$.
Larger particles scatter light at the ____ end of the spectrum.
Report Question
0%
Blue
0%
Green
0%
Violet
0%
Red
Explanation
Larger particles scatter light at the
red
end of the spectrum. Because amount of scattering decreases with increase in wavelength.
Myopia may arise due to ____ .
a. Elongation of eyeball
b. Shrinking of the eyeball
c. Long focal length of the eye
d. Increased curvature of the eye lens
Report Question
0%
a and b
0%
b and c
0%
c and d
0%
a and d
Explanation
A person with myopia can see nearby objects clearly but cannot see distant objects distinctly. A person with this defect has the far point nearer than infinity. In a myopic eye, the image of a distant object is formed in front of the retina and not at the retina itself either because of the excessive curvature of the eye lens or elongation of the eyeball.
Hypermetropia may arise due to _____:
a. Shrinking of the eyeball.
b. Elongation of eyeball.
c. Long focal length of the eye.
d. Excessive curvature of the eye lens.
Report Question
0%
b and c
0%
a and c
0%
a and d
0%
b and d
Explanation
Hypermetropia is a refractive defect of the eye in which the person is unable to see nearby objects clearly. The near point is farther away from the normal near point (25 cm). This happens because the light rays from a nearby object focus at a point behind the retina. Hypermetropia arises either because the focal length of the eye lens is too long which increases the near point, or the eyeball has become too small which makes it difficult to form the image at the retina.
Which of the following statements are true for presbyopia?
Report Question
0%
Decreased power of accommodation
0%
Weak ciliary muscles and reduced flexibility of eye lens
0%
Usually occurs with increasing age
0%
All of the above
Explanation
In Presbyopia, t
he power of accommodation of the eye gradually decreases with age. For most people, the near point moves further away from 25cm. Sometimes, a person may suffer from both myopia and hypermetropia. This defect arises due to the gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens.
So option A, B, C are correct. The answer is option D.
Why do high rise buildings have a red light on the top of the building?
Report Question
0%
Red light is the least scattered by fine particles
0%
Red light can be easily spotted by the pilot
0%
Both A and B
0%
None
Explanation
Red light is the least scattered by fine particles, fog or smoke present in the atmosphere which makes it easier to detect it clearly and distinctly so that
pilot gets notification that
there is
some object and
avoid from any collision.
The condition occurring due to gradual decrease in power of accommodation because of ageing is called ____ .
Report Question
0%
Near-sightedness
0%
Hypermetropia
0%
Presbyopia
0%
Cataract
Explanation
The power of accommodation of the eye gradually decreases with age. For most people, the near point moves further away from 25cm. Sometimes, a person may suffer from both myopia and hypermetropia. This defect is called Presbyopia. It arises due to the gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens.
How does concave lens correct myopia?
Report Question
0%
Increases the curvature of the eye lens
0%
Forms the image of the object at the retina
0%
Decreases the elongation of the eyeball
0%
All of the above
Explanation
A person with myopia cannot see distant objects clearly since the far point for that person is nearer than infinity. Such a person may see clearly up to a distance of a few meters. In this condition, the image of a distant object is formed in front of the retina and not at the retina itself. A concave lens of suitable power will bring the image back on to the retina and thus the defect is corrected.
Which of the following statements are true for hypermetropia?
a. The near point is farther away from 25cm.
b. The image of the object is formed behind the retina.
c. It arises due to decreased power of accommodation.
d. It can be corrected by the diverging lens.
Report Question
0%
$$b$$ and $$c$$
0%
$$c$$ and $$d$$
0%
$$a$$ and $$b$$
0%
$$a$$ and $$d$$
Explanation
A person with hypermetropia can see distant objects clearly but cannot see nearby objects distinctly. The near point, for the person, is farther away from the normal near point $$(25\ cm)$$. This is because the light rays from a nearby object are the focus at a point behind the retina either because the focal length of the eye lens is too long or the eyeball has become too small.
It can be corrected by the converging lens.
The following conditions are seen in which defect of vision?
a. The vision is clear up to a distance of few meters
b. It may occur due to elongation of eyeball
c. The image of the object is formed in front of the retina
Report Question
0%
Myopia
0%
Cataract
0%
Presbyopia
0%
Hypermetropia
Explanation
A person with myopia cannot see distant objects distinctly since the far point for that person is nearer than infinity. Such a person may see clearly up to a distance of a few meters. In this condition, the image of a distant object is formed in front of the retina and not on the retina itself. This defect may arise either due to excessive curvature of the eye lens or elongation of the eyeball. A concave lens of suitable power can correct this defect.
Presbyopia can be corrected with the help of _____ .
Report Question
0%
Bifocal lens
0%
Diverging lens
0%
Convex lens
0%
All of the above
Explanation
Presbyopia occurs due to gradual decrease in the power of accommodation of the eye with ageing. It arises due to the gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens. The person may suffer from both myopia and hypermetropia. Such people often require bifocal lenses which consist of both concave and convex lenses. The upper portion consists of a concave lens which facilitates distant vision. The lower part is a convex lens which facilitates near vision.
Why does sun appear reddish at sunrise and sunset?
Report Question
0%
Near the horizon it passes through thick layers of atmosphere having larger particles
0%
Sunlight travels longer distance at sunrise and sunset
0%
Both A and B
0%
None of the above
Explanation
Near the horizon sunlight passes through thicker layers of air having larger particles that scatter light of longer wavelength such as the red end of the spectrum. Also it travels larger distance at horizon before reaching the earth. However, light from the Sun overhead travels relatively shorter distance. At noon, the Sun appears white as only a little of the blue color is scattered whereas, near the horizon, most of the light of shorter wavelength at the blue end of the spectrum are scattered away by the small particles of the atmosphere. Therefore, the light that reaches our eyes is of longer wavelength which gives rise to the reddish appearance of the Sun.
The phenomenon of scattering of light by fine particles is called _____ :
Report Question
0%
Snell's law
0%
Dispersion effect
0%
Law of refraction
0%
Tyndall effect
Explanation
The earth's atmosphere is a heterogeneous mixture of minute particles like smoke, tiny water droplets, suspended particles of dust, and molecules of air. When a beam of light strikes such fine particles, the path of the beam becomes visible. This phenomenon of scattering of light by such kinds of colloidal particles is called Tyndall effect.
The phenomenon of dispersion proves that:
Report Question
0%
white light is made up of seven constituent colours
0%
light moves in a straight line
0%
light passes through a transparent medium
0%
light does not pass through an opaque medium and absence of light causes shadow
Explanation
The splitting of white light into its constituent colours as it passes through a refracting medium (such as prism) is known as dispersion. The phenomenon of dispersion shows that white light is made up of seven constituent colours.
Very fine particles mainly scatter _____ light.
Report Question
0%
Blue
0%
White
0%
Red
0%
Violet
Explanation
The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end.
During dispersion through prism, red light travels fastest and violet travels slowest of all the seven colours. As a result:
Report Question
0%
red bends the least and violet bends the most
0%
red bends the most and violet bends the least
0%
both red and violet bend the least of all colours
0%
both red and violet bend the most of all colours
Explanation
The speed of red light is fastest and therefore there is least bending of red light whereas the speed of the violet light is slowest and hence it bends the most of all the colours.
All other colours lie in between.
In the context of scattering
Fine particles : ____ wavelength : : large particles : _____ wavelength
Report Question
0%
Long, short
0%
Short, long
0%
Visible, infrared
0%
None of these
Explanation
Fine particles scatter light of shorter wavelength at the blue end of the spectrum and larger particles scatter light of longer wavelength at the red end of the spectrum.
Which of the following are examples of scattering of light?
Report Question
0%
Blue color of the sky
0%
Reddening of the sun at sunrise and sunset
0%
Color of water in deep seas and oceans
0%
All of the above
Explanation
The molecules of water and other fine particles in the atmosphere scatter light of shorter wavelengths at the blue end than light of longer wavelengths at the red end. Thus, when sunlight passes through water and air, the fine particles scatter the blue color more strongly than red. This scattered blue light enters our eyes and makes the ocean and sky appear blue. Near the horizon sunlight passes through thicker layers of air having larger particles that scatter light of longer wavelength such as the red end of the spectrum. Also it travels larger distance at horizon causing most of the light of shorter wavelength at the blue end of the spectrum to scatter away by the small particles of the atmosphere before reaching the earth.
Option D.
The color of scattered light depends on ____ of the scattering particles.
Report Question
0%
shape
0%
material
0%
size
0%
all of the above
Explanation
The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end. Whereas, larger particles scatter light of longer wavelengths at the red end.
Why does the sky appear blue?
Report Question
0%
The color of water is reflected on the sky
0%
Fine particles in the atmosphere scatter light of shorter wavelength
0%
The water molecules in the atmosphere makes the sky appear blue
0%
None of these
Maximum and minimum scattering in visible range are respectively:
Report Question
0%
Violet and red
0%
Red and violet
0%
Blue and green
0%
None of the above
Explanation
Violet light scatters the most while red light scatters the least because violet has shorter wavelength and red light has larger.
Very fine particles scatter:
Report Question
0%
Blue light
0%
Red light
0%
Green light
0%
White Light
Explanation
The color of the scattered light depends on the size of the scattering particles. Very fine particles scatter mainly blue light because blue has the shortest wavelength, while particles of larger size scatter light of longer wavelengths.
Scattering of light is defined as:
Report Question
0%
Splitting of light into its component colours
0%
Deflection of light in different directions when light is incident on extremely small particles
0%
Bending of light on change of medium
0%
reversal of light direction from a shiny surface
Explanation
The phenomenon of scattering occurs when light is incident on very small particles and is deflected in all directions as a result of it.
Why are danger signals Red Coloured
Report Question
0%
Human eye is most sensitive to red colour
0%
Red light is scattered most by the atmosphere
0%
Red light is scattered least by the atmosphere
0%
Red is a terrifying colour
Explanation
The red colour has the longest wavelength. So it scatters least by the particles in the atmosphere. Since red light is scattered least by the atmosphere, red is visible from large distances and is thus used for danger signals.
In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:
Report Question
0%
Blue
0%
Red
0%
Green
0%
Yellow
Explanation
Colloidal solution of sodium thiosulphate consists of fine particles that mainly scatters blue light. Hence, it appears blue from the side of the beaker.
Alternate inverted prisms are placed in series. Choose correct options.
Report Question
0%
Even number of prisms does not produce a spectrum
0%
Odd number of prisms produce a spectrum
0%
More the number of prisms, less is the intensity of emergent ray/spectrum
0%
All of above
Explanation
When a single prism is present, it splits white light into seven colours. However, combination of two inverted prisms behaves similar to a parallel glass slab and the effect is just lateral displacement of light ray.
Hence, after every two prisms we get a new ray of white light. Hence, odd number of prisms produce a spectrum and even number of prisms just laterally shifts the white light.
At every surface, a part of light is reflected and a part is transmitted. Hence, after every prism light loses some intensity. Hence, more number of prisms reduces the intensity more.
Why astronauts see dark sky in space unlike blue sky on earth:
Report Question
0%
There is no day in space
0%
Light is not scattered in space since there are no particles present
0%
Light is reflected back from the body of the astronaut
0%
Light is absorbed by the space
Explanation
The sky appears blue because of the presence of the atmosphere which scatters blue light. Space has no atmosphere and no light is scattered, hence it appears dark.
Why sky appears reddish orange at sunrise or sunset?
Report Question
0%
Sunlight suffers dispersion and only reddish light reach our eyes
0%
Sunlight experiences different degree of refraction due to change in density during night
0%
Sunlight has to travel longer path and blue light is scattered away, while red and yellow light is scattered least
0%
The reflection of earth's surface from horizon produces reddish orange colour
Explanation
White light is a combination of all the lights. During sunrise/sunset, rays have to travel larger distances and as red light scatters least, it is capable to reach our eyes while rest of the components are scattered away. Hence, sky appears reddish orange during sunrise or sunset.
0:0:1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
0
Answered
0
Not Answered
0
Not Visited
Correct : 0
Incorrect : 0
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Practice Class 10 Physics Quiz Questions and Answers
<
>
Support mcqexams.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page
