Tag: formation of image by a pinhole camera

Questions Related to formation of image by a pinhole camera

Shadow formation is an example of :

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. rectilinear propagation of light

  2. curvilinear propagation of light

  3. dispersion of light 

  4. none of these

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Correct Option: A
Explanation:

Rayleigh Scattering is responsible for the formation of shadows which is phenomena of rectilinear propagation of light . Shadows are created when an object, animal or person blocks out a portion of a light source. Shadows form in the opposite direction of whatever is blocking that source.

Select the odd one out (shadows, eclipses, expansion, images)

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. expansion

  2. shadows

  3. eclipses

  4. images

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Correct Option: A
Explanation:

Expansion is related to heat others are related to light

State whether true or false.
Shadows, eclipses and images are formed due to the rectilinear propagation of light.

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. True

  2. False

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Correct Option: A
Explanation:
Effects of rectilinear propagation of light - Formation of shadow, Formation of eclipse, Formation of images, etc

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.

Beam of light incident on a plane forms a real image of reflection. The incident beam is:

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. Parallel

  2. Convergent

  3. Divergent

  4. None of the above

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Correct Option: B
Explanation:

Convergent beam of light when incident in a plane mirror forms real image.

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.

A ray of sunlight enters a spherical water droplet $(n = \dfrac{4}{3})$ at an angle of incidence $53^\circ$ measured with respect to the normal to the surface. It is reflected from the back surface of the droplet and re-enters into air. The angle between the incoming and outgoing ray is [Take $\sin \ 53^\circ = 0.8$]

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. $15^\circ$

  2. $127^\circ$

  3. $138^\circ$

  4. $30^\circ$

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Correct Option: B
Explanation:

The angle between the incoming and outgoing ray is $180^o-53=127$.

A small plane mirror kept at the centre of a sphere of diameter $3\ m$, makes $12$ revolution per second. A thin light beam is made incident on the mirror. The linear speed of the light spot on the sphere, formed after reflection from the mirror is :

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. $18\pi\ m/s$

  2. $36\pi\ m/s$

  3. $72\pi\ m/s$

  4. $144\pi\ m/s$

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Correct Option: D
Explanation:

When plane mirror rotates through an angle $\theta$ , the reflected ray rotates through an angle 2$\theta$. So spot on the screen will make 2 x 12 = 24  revolution per second.

 
To find the velocity 
v=2$\pi$R x frequency 
=2$\pi$ x 3 x 24
=144$\pi$ m/s

 D is the Correct answer.
 

Intensity of light due to a point source at a distance $2m$ is $20$ units. The intensity due to the same source at a distance of $4m$ is

physics light and shadow formation of image by a pinhole camera pinhole camera shadow

  1. $2.5\ units$

  2. $6\ units$

  3. $80\ units$

  4. $5\ units$

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Correct Option: D