Question

When is the Tyndall effect observed?

(A)The diameter of the dispersed particles is much smaller than the wavelength of the light used.

(B)The diameter of the dispersed particle is not much smaller than the wavelength of the light used.

(C)The refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude

(D)The refractive indices of the dispersed phase and dispersion medium differ greatly in magnitude.

• A. (A) and (D)
• B. (B) and (D)
• C. (A) and (C)
• D. (B) and (C)

Answer 1

The correct option is B

(B) and (D)

Explanation for the correct options:

B. B and D.

• Tyndall effect is defined as the scattering of light when a beam of light passes in all directions through a colloid.
• The bright cone of the light is known as the Tyndall cone.
• This effect is only observed in two conditions-
• The diameter of the light is not smaller than the wavelength used.
• The Refractive index of the dispersed phase differs greatly in magnitude.

Final answer: The correct answer is option B (B and D).