Human Eye and Colourful World Test

Result

Human Eye and Colourful World Test - 23

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

When a white light ray falls on a prism, the ray at its first surface suffers:

A
no refraction

B
only dispersion

C
only deviation

D
both deviation and dispersion

Solution

When a white light ray falls on the first surface of a prism, light rays of different colours due to their different speeds in glass get refracted (or deviated) through different angles. Thus, the dispersion of white light into its constituent colours takes place at the first surface of prism.
Question 2
1 / -0

Identify the part 'A' from the shown figure of human eye :

A
Retina

B
Cornea

C
Pupil

D
Iris

Solution

Pupil is the hole present near the centre in human eye. It is the opening within the iris through which light passes before reaching the lens to get focused onto the retina. Thus, option $$C$$ is correctly represented by $$A$$ in the figure.
Question 3
1 / -0

The band of colours obtained on a screen on passing white light through a prism is called :

A
a spectrum

B
a dispersion band

C
scattering

D
none of these

Solution

Dispersion is the phenomenon of splitting of polychromatic light into its constituent colours. The band of colours obtained on the screen on passing white light through a prism is called a spectrum.
Question 4
1 / -0

The least distance of distinct vision for a normal person is about :

A
1 m

B
$$0.5\;m$$

C
$$0.25\;m$$

D
$$25 \ m$$

Solution

The minimum distance, at which objects can be seen most distinctly without strain, is called the least distance of distinct vision. It is also called the near point of the eye. For a young adult with normal vision, the near point is about 25 cm which is equivalent to 0.25 m, thus option $$C$$ is correct.
Question 5
1 / -0

The near point of a myopic eye is $$15$$ cm. What should be the power of the lens which will enable the eye to read a book placed at $$30$$ cm?

A
$$3.33$$ dioptre

B
$$-3.33$$ dioptre

C
$$2.22$$ dioptre

D
$$-2.22$$ dioptre

Solution

Given:- v=-15cm
u=-30cm
from lens formula.
$$\cfrac { 1 }{ v } -\cfrac { 1 }{ u } =\cfrac { 1 }{ f } =\cfrac { 1 }{ -15 } +\cfrac { 1 }{ 30 } =\cfrac { 1 }{ f } $$

$$\cfrac { 1 }{ f } =\cfrac { -1 }{ 30 } { cm }^{ -1 }$$ .
So power of lens = $$\cfrac { 1 }{ { f }} =\cfrac { -1 }{ 0.3 } { m }^{ -1 }$$
P= -3.33D.
Question 6
1 / -0

Why are school buses painted with yellow colour?

A
Because yellow colour make the vehicles look good

B
Our eyes are mostly sensitive to yellow colour

C
Our eyes are least sensitive to yellow colour

D
All are true

Solution

School buses are painted with yellow colour because our eyes are mostly sensitive to yellow colour (and are least sensitive for violet and red colours). So, school buses can be easily spotted by other drivers around and a safe distance can be maintained to ensure safety of children.
Question 7
1 / -0

It is very difficult to see through fog because

A
of scattering of light

B
of total internal reflection

C
fog is good absorber of light

D
refractive index offog is very large

Solution

Scattering is a phenomenon of forcing the deviation of light ray from its regular trajectory.Hence visibility in fog is less.
Question 8
1 / -0

One cannot see through fog because .......... .

A
Fog absorbs light

B
Refractive index of fog is unity

C
Light suffers total internal reflection at the droplets in fog

D
Light is scattered by the droplets in fog

Solution

Answer is D.
We cannot see through fog because of scattering.
Atoms and molecules in the air, including anything carried in the air like dust or smoke, will scatter light. Water droplets, as they are present in fog, also scatter light. The light falling on an object and reflected to a viewer can be scattered to heck and back before it gets to the place where it can be 'seen' by an observer. So the observer just sees a 'whiteout' instead of being able to make out anything beyond a few meters or so.
Question 9
1 / -0

Motion pictures or cinematography make use of :

A
Least distance of distinct vision

B
Persistence of vision

C
Power of accommodation

D
None of these

Solution

Persistence of vision is the phenomenon when eye and brain hold on to a series of images to form a single complete picture.
It refers to the optical illusion whereby multiple discrete images blend into a single image in the human mind and believed to be the explanation for motion perception in cinema and animated films.
Hence Motion pictures or cinematography make use of persistence of vision.
Question 10
1 / -0

Lens of an eye is a transparent spherical structure which:

A
reflects light

B
scatters light

C
refracts light

D
diffracts light

Solution

The lens is a transparent structure behind the iris, the coloured part of the eye. The lens bends light rays so that they form a clear image at the back of the eye – on the retina. As the lens is elastic, it can change shape, getting fatter to focus close objects and thinner for distant objects.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Human Eye and Colourful World Test - 23

Result

Human Eye and Colourful World Test - 23

Score

-

Rank

-

SHARING IS CARING

Question 1

no refraction

only dispersion

only deviation

both deviation and dispersion

Solution

Question 2

Retina

Cornea

Pupil

Iris

Solution

Question 3

a spectrum

a dispersion band

scattering

none of these

Solution

Question 4

1 m1m1m

$$0.5\;m$$

$$0.25\;m$$

$$25 \ m$$

Solution

Question 5

$$3.33$$ dioptre

$$-3.33$$ dioptre

$$2.22$$ dioptre

$$-2.22$$ dioptre

Solution

Question 6

Because yellow colour make the vehicles look good

Our eyes are mostly sensitive to yellow colour

Our eyes are least sensitive to yellow colour

All are true

Solution

Question 7

of scattering of light

of total internal reflection

fog is good absorber of light

refractive index offog is very large

Solution

Question 8

Fog absorbs light

Refractive index of fog is unity

Light suffers total internal reflection at the droplets in fog

Light is scattered by the droplets in fog

Solution

Question 9

Least distance of distinct vision

Persistence of vision

Power of accommodation

None of these

Solution

Question 10

reflects light

scatters light

refracts light

diffracts light

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

1 m