Tyndall effect is observed when
- (A)The diameter of dispersed particles is similar to the wavelength of light used.✓ Correct
- (B)The diameter of dispersed particles is much larger than the wavelength of light used.
- (C)The refractive index of dispersed phase is greater than that of the dispersion medium.
- (D)The diameter of dispersed particles is much smaller than the wavelength of light used.
Answer: (A)
Solution
The Tyndall effect is the scattering of a light beam by the dispersed particles of a colloid, and it is seen when those particles have diameters comparable to the wavelength of the light used. Particles much smaller scatter too feebly, and much larger ones no longer form a colloid, so the condition is that the particle diameter be similar to the wavelength of the light.
JEE Main · 2020 · 03 Sep 2020 · Shift 1 · Single correct option