The refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude.
The diameter of the dispersed particles is much smaller than the wavelength of the light used.
During projection of movies in the cinemas hall, Tyndall effect is noticed.
It is used to distinguish a true solution from a colloidal solution.
Show Solution
The Correct Option isB
Solution and Explanation
The Tyndall effect is the scattering of light as it passes through a colloidal solution, making the path of the light visible. This phenomenon is used to distinguish between a true solution and a colloidal solution. Here, we need to identify the incorrect statement regarding the Tyndall effect from the given options.
The refractive indices of the dispersed phase and the dispersion medium differ greatly in magnitude.
This statement is true. A significant difference in the refractive indices results in effective light scattering, leading to the visible path characteristic of the Tyndall effect.
The diameter of the dispersed particles is much smaller than the wavelength of the light used.
This statement is incorrect. For the Tyndall effect to occur, the diameter of the dispersed particles should be comparable to or larger than the wavelength of the light. If the particles are much smaller, the scattering is negligible.
During the projection of movies in the cinema hall, the Tyndall effect is noticed.
This is a true statement. The projection beam is often visible due to dust or smoke particles scattering the light, demonstrating the Tyndall effect.
It is used to distinguish a true solution from a colloidal solution.
This statement is true. The Tyndall effect is commonly used for this purpose because a true solution does not scatter light, while a colloidal solution does.
Therefore, the correct answer is that the diameter of the dispersed particles is much smaller than the wavelength of the light used, as this situation would not result in the Tyndall effect.
