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Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

C.V Raman's major contribution was on

  1. Inelastic scattering of light by molecules

  2. Quantum statistics

  3. Theory of super conductivity

  4. Expanding universe
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A

It is also possible for the incident photons to interact with the molecules in such a way that energy is either gained or lost so that the scattered photons are shifted in frequency. Such inelastic scattering is called Raman Scattering.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.

  1. both assertion and reason are true but the reason is the correct explanation of assertion

  2. both assertion and reason are true but the reason is not the correct explanation of assertion

  3. assertion is true but reason is false

  4. both the assertion and reason are false

  5. reason is true but assertion is false
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Setting sun appears to be red because red light which has greatest wavelength is least scattered and reaches our eyes the most. Other wavelength are scattered to the longest extent. So, reason given is wrong.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

Assertion: By roughening the surface of a glass sheet its transparency can be reduced.
Reason: Glass sheet with rough surface absorbs more light.

  1. Both assertion and reason are true and reason is the correct explanation of assertion

  2. Both assertion and reason are true but the reason is not the correct explanation of assertion

  3. Assertion is true but reason is false.

  4. Both the assertion and reason are false

  5. Reason is true but assertion is false
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
When a glass surface is made rough, light falling on it gets scattered. Due to this, transparency of glass is reduced.
Hence, assertion is correct and reason is wrong.
Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:

  1. Blue

  2. Red

  3. Green

  4. Yellow
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Colloidal solution of sodium thiosulphate consists of fine particles that mainly scatters blue light. Hence, it appears blue from the side of the beaker.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

When is the direction of scattered light independent of the wavelength?

  1. Medium of travel is not air.

  2. Particles involved in scattering have size smaller than the wavelength of the incident light wave.

  3. Particles involved in scattering have size larger than the wavelength of the incident light wave.

  4. Particles scattering the light wave are not neutral in charge.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Particles smaller than the wavelength of light scatters the light in all directions. In visible spectrum, they scatter violet the most and red the least. However, when the particles are larger than the wavelength of light, then the scattering of all wavelengths occur to same extent.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

Multiple choice physics effects of light scattering of light and its applications some natural phenomena of light natural phenomena explained by scattering

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
Reveal answer Fill a bubble to check yourself
A Correct answer
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)

Multiple choice physics parametric equations proving properties of curves derivatives - introduction and interpretation introduction to calculus - differentiation

If slope of tangent of curve $y=\dfrac{x}{b-x}$ at $(1,1)$ be $2$ then $b=$

  1. $1$
  2. $2$
  3. $0$
  4. $-1$
  5. $-2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Given,

$y=\dfrac{x}{b-x}$
Now,
$\dfrac{dy}{dx}=\dfrac{(b-x)1+x.(-1)}{(b-x)^2}$
or, $\dfrac{dy}{dx}=\dfrac{b}{(b-x)^2}$.
Now,
$\left.\dfrac{dy}{dx}\right| _{(1,1)}=\dfrac{b}{(b-1)^2}$.
According to the problem,
$\dfrac{b}{(b-1)^2}=2$
or, $b=2(b^2-2b+1)$
or, $2b^2-5b+2=0$
or, $(2b-1)(b-2)=0$
or, $b=\dfrac{1}{2}, 2$.

Multiple choice physics parametric equations proving properties of curves derivatives - introduction and interpretation introduction to calculus - differentiation

The general solution of the differential equation $\sin{2x}\left( \cfrac { dy }{ dx } -\sqrt { \tan { x }  }  \right) -y=0$ is $y\phi(x)=x+c$ then ${ \Phi  }^{ 1 }\left( \cfrac { \pi  }{ 4 }  \right) $ is _____

  1. $1$
  2. $-1$
  3. $\cfrac{1}{\sqrt{3}}$
  4. $\sqrt{-3}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$\displaystyle \frac{dy}{dx}-\text{cosec}2x y=\sqrt{\tan x};I.F=e^{\displaystyle \int-\text{cosec}2xdx}$

$=\sqrt{\text{cosec }2x+\text{cot} 2x} \implies y\sqrt{\text{cosec}2x+\text{cot}2x}=x+c\implies \phi'\bigg(\frac{\pi}{4}\bigg)=-1$