Tag: physics

Questions Related to physics

Two pont white are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye ? [Take wavelength of light = 500 nm]

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

  1. 5 m

  2. 1 m

  3. 6 m

  4. 3 m

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Correct Option: A

If you read the words of your book, the reflection is

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

  1. specular reflection

  2. diffused reflection

  3. may be specular may be diffused

  4. None of these

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Correct Option: B

Image formation takes place by

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

  1. specular reflection

  2. diffused reflection

  3. Both (a) and (b)

  4. None of these

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Correct Option: A

The distance of the eye-lens from the retina is $x$. For a normal eye, the maximum focal length of the eye-lens

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

  1. $= x$

  2. $< x$

  3. $> x$

  4. $= 2x$

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Correct Option: A
Explanation:

Focal length of normal eye lens is equal to the distance between eye-lens and retina i.e, $x$  so that all rays converges on retina after passing through  eye-lens

The persistence of vision for normal human eye is :

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

  1. $1/{ 10 }^{ th }$ of a second

  2. $1/{ 16 }^{ th }$ of second

  3. $1/{ 6 }^{ th }$ of a second

  4. None of these

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Correct Option: B

Refraction of light in the eye occurs at ............

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

  1. The lens only

  2. Cornea only

  3. both cornea and lens

  4. The Pupil

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Correct Option: C

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

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

  1. the eye can focus on very rapidly changing pictures

  2. eye is quicker than the brain

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

  4. the optical cortex can see through the rapidly moving images

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Correct Option: C
Explanation:

Human eye cannot differentiate two images when the interval of separation between them is less than one-tenth of a second

Which part of human eye controls the amount of light entering the eye?

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

  1. Cornea

  2. Retina

  3. Pupil

  4. Iris

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Correct Option: D
Explanation:

Correct answer is (D)

Iris is the ring of pigmented tissue surrounding the pupil that varies in color from person to person, it contract and dilates to control the amount of light entering the eye through the pupil. The pupil is the opening in the center of the iris where light enters the eye. 

The presistence of the eye is only for:

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

  1. 1/100th of a second

  2. 1/120th of a second

  3. 1/16th of a second

  4. 1/200th of a second

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Correct Option: C
Explanation:

According to Persistence of Vision theory, the human eye has the illusion of an after image still persisting. It is when our eye has the ability to persist for 1/16 of a second after the image has removed. It is used in animation to show fluent movement, normally after every two frames one picture would be shown, so for every 24 frames 12 pictures will be shown. This gives us the illusion of movement and the afterimage persists on our retina. 

Which of the following is Not an advantage of having two eyes?

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

  1. It gives a wider field view.

  2. The ability to detect faint objects is enhanced with two detectors instead of one.

  3. It gives the ability to interpret the closeness of an object.

  4. It gives the eye higher protection from dust and pollution.

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Correct Option: D
Explanation:

There are several advantages of our having two eyes instead of one.
(i) It gives a wider field view because human being has a horizontal field view of about 150∘150∘ with one eye and of about 180∘180∘with two eyes.
(ii) The ability to detect faint objects is enhanced with two detectors instead of one.
(iii) With one eye, the world looks flat, i.e., two dimensional-only. With two eyes, the view is three dimensional.
As our two eyes are separated by a few centimeters each eye observes a slightly different image. Our brain combines the two views into one and we get to know how close or far away the things observed are.