Question

Tyndall effect is applicable when:-
THIS QUESTION HAS MULTIPLE CORRECT ANSWER
A.the diameter of the dispersed particle is not much smaller than the wavelength of the light used
B.the diameter of the dispersed particles is much smaller than the wavelength of the light used
C.the refractive indices of the dispersed phase and the dispersion medium are the same
D.the refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude

Answer 1

Hint:
The Tyndall effect is defined as the process of scattering of light when light passes through a colloid. The Tyndall effect occurs in colloids as they contain macroparticles that can scatter the light. Tyndall effect to be seen the particles should be not so smaller than the wavelength of the light use as if particles are so small they will not scatter the light coming in their path. The refractive indices should greatly differ as if this will not happen the light bean can not be scattered or the light beam scatter so weakly that it can not be seen.

Complete answer:

                     Tyndall effect in the canopy of the forest.
A.If the diameter of the dispersed particle is not much smaller than the wavelength of the light used then this option should be correct as particles should be smaller to observe the scattering of light.
Now talking about Option B-If the diameter of particles will be less small then no scattering will be observed as they will not be able to scatter the wavelength so higher. Hence the option is wrong
NOw if we’ll go through Option C then it states that the refractive indices of the dispersed phase and the dispersion medium are the same as the light would not show refraction as two mediums will not differ. Hence the option C is incorrect
Now at last but not least Option D says that the refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude so now since The refractive indices when differs the light shows bend from one medium to another’s and so the light scatters. So this option is also correct.

And hence Our correct answer is A and D.

Note: The applications where tyndall effect is observed are:-
When a beam enters a room through a hole, it gets illuminated because the light beam is scattered by randomly moving dust particles in the room.
In the dense forest, particularly in every morning, there is a fog, tiny droplets of water are suspended in the air. These particles are large enough to scatter a beam of light. Hence the Tyndall effect is observed