Tag: human eye and colourful world

Quizzes (6) Questions (68)

Questions Related to human eye and colourful world

Multiple choice structure of human eye human eye and colourful world

The inability among the elderly to see nearby objects clearly because of the weakaning of the ciliary muscles is called

  1. Far-sightedness

  2. Near-sightedness

  3. Presbyopia

  4. Astigmatism
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The inability among the elderly to see nearby objects clearly because of the weakening of the ciliary muscles is called presbyopia.

Multiple choice structure of human eye human eye and colourful world

For a normal eye, the cornea of eye provides as converging power of 40 D and the lens least converging power of the eye lens behind the cornea is 20 D. Using this information , the distance between the retina and the cornea – eye lens can be estimated to be:

  1. 1.5 cm

  2. 5 cm

  3. 2.5 cm

  4. 1.67 cm
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Given that,

Power ${{P} _{1}}=40\,D$

Power ${{P} _{2}}=20\,D$

Total power of the combination

  $ P={{P} _{1}}+{{P} _{2}} $

 $ P=40+20 $

 $ P=60\,D $

Now, focal length of the combination

  $ f=\dfrac{1}{60}\times 100 $

 $ f=\dfrac{5}{3}\,cm $

Now, for minimum converging state of the eye lens object is at infinity

  $ u=-\infty  $

 $ f=\dfrac{5}{3} $

Now, from lens equation

  $ \dfrac{1}{f}=\dfrac{1}{v}-\dfrac{1}{u} $

 $ \dfrac{3}{5}=\dfrac{1}{v}-\dfrac{1}{\infty } $

 $ \dfrac{1}{v}=\dfrac{3}{5} $

 $ v=\dfrac{5}{3}\,cm $

So, the distance between retina and cornea – lens system $1.67\ cm$

Multiple choice physics human eye and colourful world scattering of light and its applications some natural phenomena of light effects of light

One can not see through fog because:

  1. fog absorbed light

  2. light is scattered by the droplets in fog

  3. light surfers total reflection by the droplets in the fog

  4. the refractive index of fog is in infinity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We can not see clearly through fog because the light is scattered by the droplets in the fog. The light is scattered by very small particles, this phenomenon is called Tyndall effect.

Hence the option B is the right answer

Multiple choice physics human eye and colourful world scattering of light and its applications some natural phenomena of light effects of light

The rising and setting of sun appear red because of : 

  1. refraction

  2. reflection

  3. defraction

  4. scattering
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The reddish appearance of the sun at sunrise or sunset is due to scattering of light by the molecules of air and other fine particles in the atmosphere.


Hence the option D is the right answer

Multiple choice physics human eye and colourful world human eye and its working what is inside our eyes? human eye and defects of vision

We are able to see objects around us because :

  1. The objects absorb all the light.

  2. The light reflected from the object enters our eyes.

  3. Light can be refracted.

  4. Light travels in straight lines.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We are able to see objects around us because the light reflected from the object enters our eyes.

Multiple choice physics human eye and colourful world human eye and its working what is inside our eyes? human eye and defects of vision

Which of the following statements about human eye is not true?

  1. The iris gives a distinct colour to the eye

  2. The yellow spot is extremely sensitive to light

  3. The space between lens and cornea is filled with ciliary muscles

  4. The optic nerves enters the eye near the blind spot
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The iris gives a distinct colour to the eye is false.
The yellow spot is extremely sensitive to light is false.
The space between lens and cornea is filled with ciliary muscles is true.
The optic nerves enters the eye near the blind spot is false.

Multiple choice physics human eye and colourful world human eye and its working what is inside our eyes? human eye and defects of vision

A series of fast moving still pictures can create an illusion of movement because :

  1. The eye can focus on very rapidly changing pictures

  2. Eye is quicker than the brain

  3. Eye can separate two images only when the interval of separation between them is one-tenth of a second

  4. The optical cortex can see through the rapidly moving images.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Human brain needs some time to process the images. It has the ability to see two distinct images only if the separation between them is one-tenth of a second, otherwise an illusion of continuity is created.