Tag: nature and sources of light

Questions Related to nature and sources of light

Parallel beam is

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. produced by a source at infinity

  2. produced by a source at finite distance

  3. produced by a virtual source

  4. None of these

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Correct Option: A

While moving from deep water to shallow water.

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. Frequency of the water waves decrease

  2. Frequency of the water waves increase

  3. Frequency of the water waves stays the same

  4. None of the above

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Correct Option: C

Which of the following is a unit for intensity of light?

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. Candle power

  2. Lux

  3. Both A & B

  4. None of the above

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Correct Option: C
Explanation:
In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd), an SI base unit.
Also, unit for intensity of light are:
(i) Candle Power
(ii) Lux

Which of the following statements applies to light?

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. Light can only be described as particles.

  2. Light can only be described as waves.

  3. Light can be described as rays, waves and particles.

  4. Light can only be described as rays.

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Correct Option: C
Explanation:

We can observe various phenomenon of light which cannot be explained by wave nature of light and photon nature of light some of the phenomenon are listed below:
Nature of light:                                          Phenomenon:
Ray                                                                 Reflection, Refraction
Wave                                                               Diffraction, Interference
Particle                                                  Oscillation frequency of radio waves.

Which of the following statements about the behaviour of light is not correct?

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. Interference patterns are evident for light behaving as rays.

  2. Ray properties of light are useful for understanding how images are formed by optical devices such as eyes.

  3. Wave properties are important for observing the behaviour of light at a fine scale.

  4. Both wave and particle theories of light can be related to the colour sensations produced by light.

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Correct Option: A
Explanation:

Interference patterns are explained using wave nature of light. You can learn more from youtube video "Interference of light".

Newton postulated his corpuscular theory of light on the basis of

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. newton's rings

  2. rectilinear propagation of light

  3. colour through thin films

  4. dispersion of white light into colours

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Correct Option: B
Explanation:

Rectilinear propagation of light.
According to Newton’s Corpuscular Theory of Light, light consists of very tiny particles called corpuscles. These corpuscles, on emission from the source of light, travel in straight line with high velocity.

The size of corpuscles are ________ for different colours.

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. same

  2. different

  3. either (a) or (b)

  4. None of these

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Correct Option: B
Explanation:

Different.
The corpuscles can be of different sizes. The different colors of light are due to the different sizes of the corpuscles.

According to corpuscular theory, the velocity of light in the denser medium is greater than that in rarer medium.

evs magic with mirrors dual nature of light nature and sources of light theories on light

  1. True

  2. False

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Correct Option: A
Explanation:

The corpuscles (light) would travel faster in the denser medium than in rarer medium. But later this is proved wrong. We know that light travels faster in the rarer medium than in denser medium.

State whether true or false.
In a completely dark room, if you hold up a mirror in front of you, you will still see a reflection of yourself in the mirror.

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: B
Explanation:

Since there is no source of light in the room, so reflection can't be seen in the mirror. Th given statement is thus false.

State whether true or false.
The moon is luminous body.

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: B
Explanation:

Moon reflects the light of sun and not its own light. So, moon is a non-luminous body.