Tag: some natural phenomena of light

Questions Related to some natural phenomena of light

Rising and setting sun appears to be reddish because:

  1. The sun is colder at sunrise or at sunset

  2. Diffraction sends red rays to the earth at these times

  3. Refraction is responsible for it

  4. Scattering due to dust particles and air molecules is responsible for it


Correct Option: D
Explanation:

According to Rayleigh's law of scattering, amount of scattering $\alpha \frac {1}{\lambda^4}$.
Red having maximum wavelength straight to the observer.
Most of the scattered light goes towards the sky, so the sky appears blue.

The process of re-emission of absorbed light in all directions with different intensities by the atom or molecule is called ____________.

  1. Scattering of light

  2. Dispersion of light

  3. Reflection of light

  4. Refraction of light


Correct Option: A
Explanation:

$Scattering$ is the process of absorbed light in all possible directions with different intensities and frequency by an atom or a molecule.


Answer-(A)

A beam of monochromatic light first travels through glass of R.I. $1.5$ and then through water (R.I. $=\dfrac{4}{3}$). If the difference in their wavelengths in the two media is $40$nm, then the wavelength of the monochromatic light in vacuum will be?

  1. $4000\overset{o}{A}$

  2. $4400\overset{o}{A}$

  3. $4800\overset{o}{A}$

  4. $5200\overset{o}{A}$


Correct Option: B

One can not see through fog because:

  1. fog absorbed light

  2. light is scattered by the droplets in fog

  3. light surfers total reflection by the droplets in the fog

  4. the refractive index of fog is in infinity


Correct Option: B
Explanation:

We can not see clearly through fog because the light is scattered by the droplets in the fog. The light is scattered by very small particles, this phenomenon is called Tyndall effect.

Hence the option B is the right answer

The rising and setting of sun appear red because of : 

  1. refraction

  2. reflection

  3. defraction

  4. scattering


Correct Option: D
Explanation:

The reddish appearance of the sun at sunrise or sunset is due to scattering of light by the molecules of air and other fine particles in the atmosphere.


Hence the option D is the right answer

CV Raman got the Nobel Prize for his experiment on :

  1. Dispersion of Light

  2. Reflection of Light

  3. Deflection of Light

  4. Scattering of Light


Correct Option: D
Explanation:

C. V. Raman got noble prize for his free, transparent sample of a chemical compound, a small fraction of the light emerges in directions other than that of the incident (incoming) beam. Here it is all about scattering of light.

It is very difficult to see through fog because

  1. of scattering of light

  2. of total internal reflection

  3. fog is good absorber of light

  4. refractive index offog is very large


Correct Option: A
Explanation:

Scattering is a phenomenon of forcing the deviation of light ray from its regular trajectory.Hence visibility in fog is less.

Stokes and antistokes line observed in Raman scattering is due to ________ of light.

  1. reflection

  2. inelastic scattering

  3. elastic scattering

  4. dispersion


Correct Option: B
Explanation:

Stokes and antistokes line observed in Raman scattering is due to the inelastic scattering of light.

In Raman scattering, Stokes and Antistokes lines respectively represents lines with ______ and _____ wavelength

  1. Low, High

  2. High, High

  3. High, Low

  4. Low, Low


Correct Option: C
Explanation:

In raman scattering stokes lines are the high wavelength & antistokes have least wavelength in the scattered light.

In Raman effect, the wavelength of the incident radiation is $5890\overset{o}{A}$. The wavelengths of Stocks and anti-stocks lines are respectively.

  1. $5880\overset{o}{A}$ and $5900\overset{o}{A}$

  2. $5900\overset{o}{A}$ and $5880\overset{o}{A}$

  3. $5900\overset{o}{A}$ and $5910\overset{o}{A}$

  4. $5870\overset{o}{A}$ and $5880\overset{o}{A}$


Correct Option: B
Explanation:

Incident wavelength=$5890 A^{0}$

  • Stocks  lines have wavelength more than the incident radiation
$\lambda _{s}>$ incident wavelength
  • Anti stocks lines have wavelength less than incident radiation
$\lambda _{as}<$ incident wavelength
So the correct option is B