Rheology is the scientific study of:

• The resistance of solids to compression

• The flow phenomena and deformation of matter

• The deformation of gases under stress

• The resistance of liquids to temperature change

Viscosity is defined as:

• The speed at which a fluid moves through a tube

• The measure of a fluid's resistance to shear or tensile stress

• The density difference between two fluids

• The rate at which a liquid flows in response to gravity

Which unit is commonly used to measure dynamic viscosity?

• Stokes

• Pascal seconds (Pa.s)

• Centimeter per second

• Centipoise (cP)

What is the primary difference between dynamic and kinematic viscosity?

• Kinematic viscosity measures resistance to external forces, while dynamic viscosity measures inherent viscosity.

• Dynamic viscosity measures the resistance to flow under an external force, while kinematic viscosity measures the resistive flow under the influence of gravity.

• Dynamic viscosity is only used for non-Newtonian fluids

• Kinematic viscosity applies only to gases

Which of the following is a characteristic of Newtonian fluids?

• Their viscosity is dependent on shear rate

• They exhibit shear thinning behavior

• They show a linear relationship between shear stress and shear rate

• They require rotational viscometers for accurate measurement

What does "shear thinning" describe in a fluid?

• Viscosity increases with increasing shear stress

• Viscosity remains constant under all shear rates

• Viscosity decreases as shear stress increases

• Viscosity increases as temperature increases

Which of the following is an example of a pseudoplastic (shear thinning) fluid?

• Toothpaste

• Ketchup

• Honey

• Chocolate

What type of fluid exhibits a decrease in viscosity when stress is applied over time?

• Rheopexy

• Thixotropy

• Shear thinning

• Shear thickening

What is the function of a rotational viscometer?

• To measure the change in fluid density

• To measure the force needed to turn a probe in a liquid sample

• To measure temperature-induced changes in viscosity

• To measure the viscosity of gases

Which of the following is the correct formula for calculating viscosity?

• Viscosity = Shear rate / Shear stress

• Viscosity = Shear stress / Shear rate

• Viscosity = Velocity gradient / Shear strain

• Viscosity = Shear rate / Density