Tag: how light travels

Questions Related to how light travels

During reflection when light gets reflected form a surface 

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. it selects the path that takes the least time

  2. it selected the path that takes the maximum time

  3. it selects the shortest path

  4. none of these

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Correct Option: A
Explanation:

it selects the path that takes the least time.

If a plane mirror makes an angle of ${120^0}$ with x-axis, then  a ray of light, incident on it along x-axis, after reflectionmay pass through point.

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. (1,1)

  2. $\left( {1,\sqrt 3 } \right)$

  3. (3,1)

  4. (1,2)

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Correct Option: B

When red glass is heated in dark room, it will seem:

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. black

  2. purple

  3. green

  4. yellow

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Correct Option: C
Explanation:

When a red glass is heated to a high temperature it will glow with green light.

Light shows:

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. Curvilinear propagation

  2. Rectilinear propagation

  3. Random propagation

  4. None of the above

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Correct Option: B
Explanation:
Light shows Rectilinear propagation.
Rectilinear Propagation of Light is the tendency of light to travel in straight Lines.

We can see the objects only when:

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. reflected light from the objects reaches our eyes

  2. the objects absorb all the light

  3. when the objects allow all the light to pass through them

  4. none of the above

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Correct Option: A
Explanation:

Objects can pnly be seen when light falls onto the object and is reflected back to our eyes to form an image on the retina.

A narrow beam of light that is moving in a defined direction is:

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. wave

  2. compression

  3. ray

  4. rarefaction

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Correct Option: C
Explanation:

A light ray is a narrow beam of light that is moving in a defined direction. Alternatively, a beam of light consists of lot of light rays parallel to each other.

We cannot see anything in a dark room because:

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. everything is black in colour

  2. our eyes do not work in darkness

  3. light from the room does not reach our eyes

  4. all the light gets scattered

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Correct Option: C
Explanation:

We can only see objects when light falls into are eyes after being reflected from the objects.

We are able to see objects because 

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. they absorb light

  2. they reflect light

  3. total internal reflection takes place in them

  4. all the light is refracted through them

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Correct Option: B
Explanation:

We can only see objects when light reflected from the object falls on our eyes.

The statment that is true about 'Light' is

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. requires a material medium to travel from one place to another

  2. does not require a material medium

  3. light has mass but it is negligible

  4. light waves are longitudinal wave

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Correct Option: B
Explanation:

Light does not require a medium to propogate. Ex: The rays from the sun.

Which of the following describes an object that allows no light to pass through it ? 

evs light and shadow nature and sources of light how light travels path of light elementary ideas of astronomy

  1. Transparent

  2. Opaque

  3. Translucent

  4. Diffuse

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Correct Option: B
Explanation:

The object, that allows no light to pass through, is called Opaque.