Tag: scattering of light and its applications

Questions Related to scattering of light and its applications

As the thickness of the atmosphere increases colour of scattered light is found in ________ order.

  1. Blue, violet, yellow, red

  2. Violet, blue, yellow, red

  3. Red, yellow, blue, violet

  4. Violet, blue, red, yellow


Correct Option: D
Explanation:

The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum because of which blue and violet light reaches our eyes from all directions.

As thickness of atmosphere increase,  more molecules are available to scatter the violet and blue light away from our eyes. If the path is long enough, all of the blue and violet light scatters out of our line of sight.  and he other colors orange, red continue on their way to your eyes.
The sky often appears red because larger particles of dust, pollution, and water vapor in the atmosphere reflect and scatter more of the reds and yellows.
Option D 

The earth's atmosphere is transparent for the visible light.

  1. True

  2. False


Correct Option: A
Explanation:

True. This is the reason we can see things around us in Earth's atmosphere.  

The clear sky appears blue because:

  1. blue light gets absorbed in the atmosphere.

  2. ultraviolet radiations are absorbed in the atmosphere.

  3. violet and blue lights get scattered more than lights of all other colours by the atmosphere.

  4. light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.


Correct Option: C
Explanation:

The scattering of light depends on the size of the dust particles and the wavelength of the light. The amount of scattering is inversely proportional to the fourth power of wavelength.
Since, violet and blue lights get scattered more than lights of all other colours by the atmosphere the sky appears blue.

What are the colours of the Sun observed most during sunrise/sunset and noon? 

  1. white and red

  2. reddish and orange

  3. yellow and reddish

  4. orange and blue


Correct Option: B
Explanation:

During sunrise and sunset the sun rays have to pass through a larger distance and also a greater thickness of air since it is low in the sky. At these positions, the sky looks orange-red colour because photons of red and orange light are least scattered through the atmosphere and are able to reach our eyes.

Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

  1. Dispersion of light

  2. Scattering of light

  3. Total internal reflection of light

  4. Reflection of light from the earth


Correct Option: B
Explanation:

We see red colour of the sun at sunrise or sunset as the sun at horizon and light rays need to travel a greater distance. In the process of scattering, violet, blue and green rays in the original sunlight are removed and the transmitted beam has yellow and red dominant.

Red light is used as danger signal because it is:

  1. Accepted as symbol

  2. Pleasing to the eye

  3. Sensitive to the eye

  4. Having high wavelength


Correct Option: D
Explanation:

Red light is used as danger signal because it is having high wavelength, less scattering ,hence can travel larger distances.

Blue colour of  sky is due to:

  1. scattering.

  2. absorption.

  3. reflection.

  4. refraction.


Correct Option: A
Explanation:

Blue light is scattered the most. Hence, as sunlight travels the earth, most of the blue colour is scattered and hence spread. This causes the sky to appear blue in the day.

Raman effect is an example of

  1. Coherent scattering of light.

  2. Incoherent scattering of light

  3. Coherent interference of light

  4. Incoherent interference of light


Correct Option: B
Explanation:

Raman effect is an example of incoherent scattering of light, as it is specific to the molecule which cause it.

Tyndall effect is applicable when?

  1. The diameter of the dispersed particle is not much smaller than the wavelength of the light used

  2. The diameter of the dispersed particles is much smaller than the wavelength of the light used

  3. The refractive indices of the dispersed phase and the dispersion medium must be same

  4. The refractive indices of the dispersed phase and the dispersion medium must differ greatly in magnitude


Correct Option: A

Which of the following statements is correctregarding the propagation of light of differentcolours of white light in air?

  1. Red light moves fastest

  2. Blue light moves faster than green light

  3. All the colours of the white light move with the same speed in empty space

  4. Yellow light moves with the mean speed as that of the red and the violet light


Correct Option: C