Tag: light, shadows and images

Questions Related to light, shadows and images

A ball of $1\ g$ released down an inclined plane describes a circle of radius $10\ cm$ in the vertical plane on reaching the bottom. The minimum height of the inclined plane is 

physics light, shadows and images introduction to reflection of light light and sight images in plane mirror

  1. $10\ cm$

  2. $15\ cm$

  3. $20\ cm$

  4. $25\ cm$

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Correct Option: A

If a ray of light passes from a denser medium to a rarer medium in a straight line, the angle of incident must be _____

physics light, shadows and images introduction to reflection of light light and sight images in plane mirror

  1. $0^o$

  2. $30^o$

  3. $60^o$

  4. $90^o$

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Correct Option: A

While is not basic transformation function 

physics light, shadows and images introduction to reflection of light light and sight images in plane mirror

  1. Translation

  2. Rotating

  3. Scaling

  4. Reflection

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Correct Option: D
Explanation:

A transformation is when you take a shape and you move it in some way. A basic rigid transformation is a movement of the shape that does not affect the size of the shape. The shape doesn't shrink or get larger. There are three basic rigid transformations: reflections, rotations, and translations. So, scaing is not a basic transformation function.

A ray of light is incident on a plane mirror along a vector $\hat i+\hat j-\hat k$. The noemal on incident point is along $\hat i+\hat j$. Then unit vector along the reflected ray is:

physics light, shadows and images introduction to reflection of light light and sight images in plane mirror

  1. $ \dfrac { 1 }{ \sqrt { 3 } } \left( \hat { i } +\hat { j } +\hat { k } \right)$

  2. $-\dfrac { 1 }{ \sqrt { 3 } } \left( \hat { i } +\hat { j } +\hat { k } \right)$

  3. $ \dfrac { 1 }{ \sqrt { 3 } } \left( -\hat { i } -\hat { j } +\hat { k } \right)$

  4. $ \dfrac { 1 }{ \sqrt { 3 } } \left( -\hat { i } +\hat { j } +\hat { k }\right)$

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Correct Option: C

State whether true or false.
A pinhole camera can take pictures of moving objects.

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. True

  2. False

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Correct Option: B
Explanation:

It is one of the disadvantage of pinhole camera that it can't take pictures of moving object.

What kind of lens is used in making a pinhole camera ?

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. Concave lens

  2. Convex lens

  3. Concavo-convex lens

  4. No lens is used

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Correct Option: D
Explanation:

A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole – effectively a light-proof box with a small hole in one side.

What is "Camera Obscura" effect ?

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. Light from a scene passes through the aperture and gets reflected from the mirror placed at the other end of the box.

  2. Light from a scene passes from one medium to another and gets refracted

  3. Light from a scene passes through the aperture and passes through a lens placed on the opposite side of the box

  4. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box

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Correct Option: D
Explanation:

A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole – effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect.

Choose the correct option from the following 

$ Statement I:$ If the size of the hole in a pinhole camera is as big as the size of a green gram then the image becomes thick and the details of the image are not clearly seen. 

$Statement II:$ If the distance of the object from pinhole camera is increased then the size of the image that is observed on the screen also increases.

$Statement III :$ If the distance between screen and hole in the pinhole camera is increasing we observe the image is becoming blurred 

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. All are correct

  2. $I, II$ are correct

  3. $II, III$ are correct

  4. $I, III $are correct

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Correct Option: A

The Image formed in a pinhole camera  is real. 

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. True

  2. False

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Correct Option: A

State the effect on the image formed by a pinhole camera if the size of the hole is increased.

physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

  1. The image becomes blurred

  2. The image gets sharper

  3. The image completely vanishes

  4. No image is formed to begin with

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Correct Option: A
Explanation:

If the size of the hole increases the image will be blurred as several 
images are formed which overlap each other