1. The particle settling velocity in a fluid–particle suspension: (a) increases with increasing ratio of particle diameter to characteristic system dimension; (b) increases with increasing particle concentration; (c) increases with increasing fluid viscosity; (d) none of the above. 2. The terminal velocity of a particle settling in a stagnant fluid: (a) increases with increasing ratio of particle diameter to characteristic system dimension; (b) increases with increasing solids concentration; (c) both (a) and (b); (d) none of the above.

One of the most challenging problems in environmental remediation is isolated blobs of contaminated fluid that become trapped in soils by capillary forces (i.e., surface tension). The pore space can be analyzed by analogy to a thin-diameter glass tube. Under the conditions given, what is the maximum length of water, I, that can be retained in the vertical glass tube shown? [mm] • contact angle 0 = 0⁰ • surface tension o= 72 dyn/cm = 0.072 N/m • tube diameter D = 2.0 mm • ● neglect the small volume of water above the meniscus the weight of water completely removes the curvature in the lower air-water interface

Some measurements on a blood sample at 37 °C (98.6 °F) indicate a shearing stress of 0.540 N/m² for a corresponding rate of shearing strain of 192 s¹. Determine (a) the apparent viscosity of the blood and (b) its ratio to the viscosity of water at the same temperature. (a) Ublood= (b) Hblood/HH2O= N*s/m²

Consider particles in suspension and their settling behaviour at different concentrations select the correct statement(s). Type 1 settling is called discrete settling. Your option is Correct B Terminal velocity in suspension is achieved when drag force is balanced by gravity force. Your answer is IN-CORRECT Correct Option 24 In Type 1 settling, for Ree(100, 300) Cn = Re 3 +0.34 (Re = Reynold's number) VRe D In Type 2 settling, the velocity of floc does not remain terminal and keeps changing as the size of the floc changes. Your option is Correct