IIT JEE , AIEEE Forum - Physics , Optics

Mr.IITIAN007

Respected Sir, please just a clear look on my comment.There is nothing
"mannerless" in my comment.As a member to an educational site, it my duty to tell the 'bads' of the site for its appropriate development. I say respectfully that,I never commented about you.

cvramana

Tyndall effect is not for FOG.

cvramana

Dear MRIITIAN007,
You should know that I am an expert in this field. So before you could say anything wrong about my answer you should veryfy 100 times what you are going to say. I do not claim I am the best. Atleast for this standard of questions I am well experienced.
I rightly agree with you that you have freedom of expression. But it should be to express your answer not to coment about others aspecially the experts.
Good luck.
GoIIT team member.

debabratanag99

Respected Sir,

Why is Tyndall effect not suitable to describe fog. As fog is also a suspension. Then why can we not use Tyndall effect for the proper explanation ??

debabratanag99

Sorry to say respected Sir,

TYNDALL EFFECT is the only answer to this question. I think it to be that. I might be wrong as my knowledge is very limited. But even the world thinks in the very similar fashion. According to the DEPARTMENT OF ENERGY, UNITED STATES OF AMERICA it is the TYNDALL EFFECT that is responsible. You can check that out at the following website link::::

http://www.newton.dep.anl.gov/askasci/eng99/eng99319.htm

I think TYNDALL EFFECT can be the only reason for FOG.

cvramana

Dear debabratanag99,

I have already given you the answer, that scattering effect is for particles smaller in size than the wavelength. The wavelength of light is approximately from 3500 A to 7500 A. Theoretical models suggest that the average cluster may encompass as many as 90 H₂O molecules at 0°C, so that very cold water can be thought of as a collection of ever-changing ice-like structures. Therefore there is no point in discussing about scattering.

This explanation is flawed for more than one reason. Fog droplets are, on
average, smaller than cloud droplets, but they still are huge compared with
the wavelengths of visible light. Thus scattering of such light by fog is
essentially wavelength independent. Unfortunately, many people learn
(without caveats) Rayleigh's scattering law and then assume that it applies
to everything. They did not learn that this law is limited to scatterers
small compared with the wavelength and at wavelengths far from strong
absorption.

karansingh

The answer is a combination of A , B , C.

As for A , water absorbs light which accounts for faintness.

As for B , due to reflection and refraction from the droplets , light is able to reach us ,but no distinct image is formed.

As for C, some part of the light may be lost due to total internal refraction leading to faintness.

But apparently, the main reason seems to be to B as it can function even without other ones and undoubtedly, causes maximum distortion.

Feel free to oppose me if i am wrong.

: Karan Singh

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