Tag: evs

Questions Related to evs

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.

The path along which light travels in a homogeneous medium is called a :

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

  1. beam of light

  2. ray of light

  3. pencil of light

  4. line of light

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Correct Option: B
Explanation:

The path along which light travels in a homogeneous medium is called a ray of light

Light waves:

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

  1. require air or another gas to travel through

  2. require an electric field to travel through

  3. require a magnetic field to travel through

  4. can travel through perfect vacuum

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Correct Option: D
Explanation:

Light is an electromagnetic wave which is transverse in nature. It does not require any material medium to pass through and can travel through vacuum.

Which of the following is a non-luminous body ?

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

  1. Sun

  2. Moon

  3. Candle flame

  4. Electric lamp

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Correct Option: B
Explanation:

Moon does not emit its own light. It reflects the light incident on it from the Sun. So, Moon is a non-luminous body.

Find out the only wrong statement in the following:

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

  1. Light travels with a speed greater than that of sound

  2. Light cannot travel through vacuum

  3. Light travels in a straight line

  4. Light has no weight

Show answer
Correct Option: B
Explanation:

Light is an electromagnetic wave which is transverse in nature. So, it does not require any material medium to pass through. Light, thus, can travel through vacuum.

A green leaf placed in a dark room is illuminated by red light. The leaf will appear to be :

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

  1. green

  2. red

  3. yellow

  4. black

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Correct Option: D
Explanation:

A green leaf can only reflect green light, so when red light is incident on it, the leaf will not be able to reflect any light making it look black