Tag: some natural phenomena of light

Questions Related to some natural phenomena of light

Why does sun appear reddish at sunrise and sunset?

  1. Near the horizon it passes through thick layers of atmosphere having larger particles

  2. Sunlight travels longer distance at sunrise and sunset

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

Near the horizon sunlight passes through thicker layers of air having larger particles that scatter light of longer wavelength such as the red end of the spectrum. Also it travels larger distance at horizon before reaching the earth. However, light from the Sun overhead travels relatively shorter distance. At noon, the Sun appears white as only a little of the blue color is scattered whereas, near the horizon, most of the light of shorter wavelength at the blue end of the spectrum are scattered away by the small particles of the atmosphere. Therefore, the light that reaches our eyes is of longer wavelength which gives rise to the reddish appearance of the Sun.

Why do high rise buildings have a red light on the top of the building?

  1. Red light is the least scattered by fine particles

  2. Red light can be easily spotted by the pilot

  3. Both A and B

  4. None 


Correct Option: C
Explanation:

Red light is the least scattered by fine particles, fog or smoke present in the atmosphere which makes it easier to detect it clearly and distinctly to avoid any obstruction.

The path of beam of light becomes _____ in a colloidal solution.

  1. visible

  2. invisible

  3. white

  4. dispersed


Correct Option: A
Explanation:

When a beam of light passes through colloidal solution, it gets scattered causing the light beam to become visible. 

In context of scattering
Fine particles : ____ wavelength : : large particles : _____ wavelength

  1. Long, short

  2. Short, long

  3. Visible, infrared

  4. None of these


Correct Option: B
Explanation:

Fine particles scatter light of shorter wavelength at the blue end of the spectrum and larger particles scatter light of longer wavelength at the red end of the spectrum.

Very large particles may scatter light of which color?

  1. Blue

  2. Violet

  3. Indigo

  4. White


Correct Option: D
Explanation:

Fine particles scatter light of shorter wavelength and larger particles scatter light of longer wavelength. However, if the size of the scattering particles is large enough, then, the scattered light may even appear white.

Why does the sky appear blue?

  1. The color of water is reflected on the sky

  2. Fine particles in the atmosphere scatter light of shorter wavelength

  3. The water molecules in the atmosphere makes the sky appear blue

  4. None of these


Correct Option: B
Explanation:

The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end. This scattered blue light enters our eyes and makes the ocean and sky appear blue.

The color of scattered light depends on ____ of the scattering particles.

  1. shape

  2. material

  3. size

  4. all of the above


Correct Option: C
Explanation:

The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end. Whereas, larger particles scatter light of longer wavelengths at the red end.

Maximum and minimum scattering in visible range are respectively

  1. Violet and red

  2. Red and violet

  3. Blue and green

  4. None of the above


Correct Option: A
Explanation:

Violet light scatters the most while red light scatters the least because violet has shorter wavelength and red light has larger.

Scattering of light  is seen when light passes through:

  1. During formation of rainbow

  2. Reflected by a mirror

  3. passed through a prism

  4. Canopy of dense forest


Correct Option: D
Explanation:

Scattering occurs when light passes through canopy of dense forests. 

Scattering of light is defined as:

  1. Splitting of light into its component colours

  2. Deflection of light in different directions when light is incident on extremely small particles

  3. Bending of light on change of medium

  4. reversal of light direction from a shiny surface


Correct Option: B
Explanation:

Phenomenon of scattering occurs when light is incident on very small particles and is deflected as a result of it.