Stokes Law is Valid for Particle Size?

Answer: C. Between 0.002mm to 0.2mm

Stokes’s law is valid for particle size between 0.002mm to 0.2mm.

Solution

Stokes law states that the force resisting a spherical body is a viscous fluid is directly proportional to the velocity of the sphere, the radius of the sphere and the viscosity of the fluid.

Settling Velocity by stokes law is given by:

V = gd²(p_s-p_w)/18μ

Where, 

V = Velocity of settling particle

D = Diameter of settling particle

g = Acceleration due to gravity

p_s = Density of settling particle

p_w = Density of water

μ = Dynamic viscosity of fluid

Stokes law is valid for particle size between 0.002mm to 0.2mm and upto a maximum Reynold’s number of 1.

☛ Related Questions:

• A Cipoletti weir is
• Which of the following is kuichling ‘s formula?
• Teak Wood is suitable for
• Increase in fineness of cement