Question

Tyndall effect is applicable when?

• 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 must be same
• D. The refractive indices of the dispersed phase and the dispersion medium must differ greatly in magnitude

Answer 1

Answer: (A), (D)

The correct options are
A The diameter of the dispersed particle is not much smaller than the wavelength of the light used
D The refractive indices of the dispersed phase and the dispersion medium must differ greatly in magnitude

$\begin{array}{c}\text{Tyndall effect is observed only when the following two}\\ \text{conditions are satisfied.}\\ \text{i) The diameter of the dispersed particles is not much}\\ \text{smaller then the wavelength of the light used}\\ \text{ii) The refractive indices of the dispersed phase and the}\\ \text{dispersion medium differ greatly in magnitude.}\\ \text{Hence option (A) and (D) are correct}\end{array}$