Tag: nature and sources of light

Questions Related to nature and sources of light

The silvering on the back surface of a mirror can be done by

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. Silver

  2. Mercury

  3. None

  4. All kind of shiny materials

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Correct Option: D
Explanation:

A plane mirror is made from a few mm thick glass plate.one surface of glass plate is polished to a high degree of smoothness which forms the front part of the mirror and the other(back)surface is silvered(I.e painted with silver,mercury or some other material.)

Light is a form of energy.

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. True

  2. False

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Correct Option: A
Explanation:

Light is a form of energy which does not require any medium to travel.

State whether true or false:
Luminous objects emit light on their own.

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. True

  2. False

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Correct Option: A
Explanation:

Luminous objects are the objects which emit light on their own by various change in form energies for example bulb or sun.

We are able to see objects around us because ______________.

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. The objects absorb all the light

  2. The light reflected from the object enters our eyes

  3. Light can be reflected

  4. Light travels in straight lines

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Correct Option: B
Explanation:

An object is visible to us only if light reflected or emitted by it reaches our eye and image is formed at retina.

When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of light rays decreases after some reflections. This is because of

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. Poor reflection from mirrors

  2. Absorption of some amount of light by mirrors

  3. Dispersion of light when the rays travel through the atmosphere

  4. Scattering of light by the mirrors

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Correct Option: B
Explanation:

The intensity of the light is decreased because no surface is perfectly reflecting surface. When the light is incident on a reflecting surface some part of the light is observed, resulting in decrease in the intensity.

State whether true or false :

A rose appears red in white light as it absorbs red color and reflects all other colors.

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

False

A rose reflects red color and absorbs other colors . That's why it appear red. 

Choose the correct option

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. Moon is a luminous object because it glows

  2. Moon is a luminous object because it is a source of light

  3. Sun is a luminous object because it is a source of light

  4. Sun is not a luminous object

Show answer
Correct Option: C
Explanation:

Objects that give out or emit light of their own are called as $ \bf{luminous\ objects} $. 
Objects which do not emit light on their own are called  $ \bf{non-luminous} $ objects.

Sun is a luminous object because it a source of light and consequently emits light of it's own.
Moon is a non-luminous object because it does not emits it's own light and glows by reflecting the light of the sun.

Hence, the correct answer is OPTION C. 

Choose the correct option regarding luminous objects

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. All objects which glow are luminous objects

  2. Objects which is not source of light is luminous objects

  3. Objects which glow can be luminous objects

  4. None of the above

Show answer
Correct Option: C
Explanation:

Luminous objects can be defined as objects which emit their own light by use of some reactions or energy source.

Which of the following is not a luminous object

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. Sun

  2. Moon

  3. Bulb

  4. candle

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Correct Option: B
Explanation:

Objects which do not emit light on their own are called  $ \bf{non-luminous} $ objects.
Objects that give out or emit light of their own are called as $ \bf{luminous\ objects} $.

Moon is a non-luminous object because it does not emits it's own light and glows by reflecting the light of the sun.
Sun, Bulb and candle give out or emit their own light and hence, are luminous objects.

Hence, the correct answer is OPTION B.

Which of the following are not non-luminous objects ?

evs light, shadows and images what makes things visible nature and sources of light light travels in straight line

  1. Moon

  2. Planets

  3. Sun

  4. Earth

Show answer
Correct Option: C
Explanation:

Objects which do not emit light on their own are called  $ \bf{non-luminous} $ objects.
Objects that give out or emit light of their own are called as $ \bf{luminous\ objects} $.

Sun is a source of light and thus, gives out or emits light of it's own and hence, is a luminous object.

Moon, planets and Earth are non-luminous objects because they do not emit light of their own and glow by reflecting the light of the sun. 

Hence, the correct answer is OPTION C.