Tag: light, shadows and images

Quizzes (6) Questions (62)

Questions Related to light, shadows and images

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

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 

  1. $10\ cm$
  2. $15\ cm$
  3. $20\ cm$
  4. $25\ cm$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

To complete a vertical circle of radius r at the bottom of an inclined plane, the minimum velocity needed at the bottom is v = sqrt(5gr). Using conservation of mechanical energy, potential energy mgh at the top of the incline converts entirely to kinetic energy at the bottom, so mgh = (1/2)mv^2 = (5/2)mgr, giving h = 2.5r = 25 cm.

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

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

  1. $0^o$
  2. $30^o$
  3. $60^o$
  4. $90^o$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When light passes from one medium to another, it only continues in a straight line without refraction if the angle of incidence is 0 degrees (normal incidence).

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

While is not basic transformation function 

  1. Translation

  2. Rotating

  3. Scaling

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

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

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:

  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)$
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice physics light, shadows and images formation of image by a pinhole camera pinhole camera shadow

What is "Camera Obscura" effect ?

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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 

  1. All are correct
  2. $I, II$ are correct
  3. $II, III$ are correct
  4. $I, III $are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All statements are correct: a large hole causes blurring (Statement I), increasing object distance decreases image size (Statement II), and increasing screen distance makes the image larger but dimmer/blurred (Statement III).

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

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

  1. The image becomes blurred

  2. The image gets sharper

  3. The image completely vanishes

  4. No image is formed to begin with
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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