Untitled Quiz

<p>Rate of shear (A)</p> Signup and view all the answers

<p>Plugin flow potentially leading to measurement errors (C)</p> Signup and view all the answers

<p>To minimize the gap causing plug flow errors (C)</p> Signup and view all the answers

<p>Using the expression that includes the weight and rpm (A)</p> Signup and view all the answers

<p>One whose time for measurement exceeds 30 seconds (C)</p> Signup and view all the answers

<p>It flows easily with low resistance to deformation. (C)</p> Signup and view all the answers

<p>Tensile force (B)</p> Signup and view all the answers

<p>Heat is dissipated and the shape remains deformed. (A)</p> Signup and view all the answers

<p>Force applied to the upper plate divided by the plate's area. (B)</p> Signup and view all the answers

<p>The movement of both plates must be equal. (D)</p> Signup and view all the answers

<p>Pascals (Pa) (B), Newtons per square meter (N/m²) (C)</p> Signup and view all the answers

<p>Shear stress (C)</p> Signup and view all the answers

<p>Elastic deformation (D)</p> Signup and view all the answers

<p>It requires a yield value to start flowing. (C)</p> Signup and view all the answers

<p>The rate of shear increases proportionally. (B)</p> Signup and view all the answers

<p>Toothpaste (A)</p> Signup and view all the answers

<p>More resistance to flow. (B)</p> Signup and view all the answers

<p>Their viscosity decreases with increasing shear rate. (D)</p> Signup and view all the answers

<p>Frictional forces and Van der Waals forces. (B)</p> Signup and view all the answers

<p>It decreases with increasing shear rate. (C)</p> Signup and view all the answers

<p>It acts as an elastic material. (D)</p> Signup and view all the answers

<p>The sample is sheared in the gap between a stationary plate and a rotating cone. (A)</p> Signup and view all the answers

<p>Stoke (D)</p> Signup and view all the answers

<p>Viscosity decreases. (C)</p> Signup and view all the answers

<p>The shearing stress produced on the cone. (C)</p> Signup and view all the answers

<p>Density (A)</p> Signup and view all the answers

<p>The ratio of the viscosity of a dispersion to that of its solvent. (D)</p> Signup and view all the answers

<p>Dilatant flow (C)</p> Signup and view all the answers

<p>The extrapolated torque value indicates the yield value. (D)</p> Signup and view all the answers

<p>Particles take on an open form of packing. (B)</p> Signup and view all the answers

<p>It results in a 10% increase in viscosity. (B)</p> Signup and view all the answers

<p>Oobleck (cornstarch and water) (A)</p> Signup and view all the answers

<p>Utilizing high-speed mixers to avoid solidification. (B)</p> Signup and view all the answers

<p>A decrease in viscosity with increased shear rate. (D)</p> Signup and view all the answers

<p>Particles are closely packed with minimal voids. (B)</p> Signup and view all the answers

<p>Viscosity increases due to insufficient vehicle to fill voids. (D)</p> Signup and view all the answers

<p>It undergoes expansion under stress. (D)</p> Signup and view all the answers

<p>The rate of structural breakdown with time at constant shear rate (C)</p> Signup and view all the answers

<p>The crystalline plates forming a house-of-cards structure (D)</p> Signup and view all the answers

<p>A significant point of structural breakdown at low shear rate (B)</p> Signup and view all the answers

<p>Thixotropic materials exhibit shear thinning behavior (B)</p> Signup and view all the answers

<p>It demonstrates a continuous thickening trend (C)</p> Signup and view all the answers

<p>It causes greater suspendability at equilibrium (C)</p> Signup and view all the answers

<p>It reverts to a sol-like state after some time (A)</p> Signup and view all the answers

<p>When the gel is fresh and has not aged (D)</p> Signup and view all the answers

A measure of a fluid's resistance to flow.

A force applied parallel to a fluid's surface.

Measure of how quickly the fluid layers slide past each other.

Fluid flow in smooth, parallel layers.

Stress caused by pulling force.

Stress caused by pushing force.

Deformation that returns to the original shape upon removal of the stress

A change in shape or form of object that doesn't return to its original shape after stress removal

A type of material flow requiring a specific shear stress (yield value) before it begins to flow.

A material exhibiting plastic flow, characterized by a yield value.

The minimum shear stress required for a Bingham body to start flowing.

The slope of a rheogram (shear stress vs. shear rate graph), representing the flow characteristic of a fluid.

The reciprocal of mobility, it measures the resistance to flow of a plastic material once the yield value is exceeded.

A material exhibiting a decrease in viscosity with increasing shear rate; no yield value.

Particles in a suspension that aggregate or stick together, causing material to exhibit a yield value.

A system where shear stress is directly proportional to shear rate, without a yield value.

A type of non-Newtonian fluid where viscosity increases with increasing shear stress.

Another name for dilatant flow, describing the property of a fluid to become thicker (higher viscosity) when subjected to shear stress.

Dilatant flow occurs because at high shear stress, particles in the fluid pack more tightly, creating larger gaps between them. The fluid then needs more force to flow because there's less lubrication between the particles.

Cornstarch mixed with water (oobleck) is a common example of a dilatant fluid. It acts like a solid when you hit it, but flows like a liquid when you pour it.

As shear stress increases, the interparticle volume (the space between particles) expands. This is because the particles try to move past each other quickly, leading to a less efficient packing.

Dilatant materials can solidify under high shear stress, which can damage processing equipment like mixers or mills.

A particle that is not clumped together with other particles. This means it's dispersed in the fluid individually.

Understanding dilatant behavior is important for processing materials like paints, inks, and cosmetics. Knowing how a fluid reacts under shear is crucial for proper mixing and handling.

Indicates how quickly a thixotropic material breaks down its structure when subjected to constant shear rate.

Indicates the degree of structural breakdown of a thixotropic material when shear rate is increased.

A characteristic feature of thixotropic systems like concentrated bentonite gel, where the up-curve of the hysteresis loop shows a bulge. This indicates a 'house-of-cards' structure due to the swelling of bentonite plates.

A sharp, pointed protrusion in the up-curve of the hysteresis loop, typical of highly structured systems like procaine penicillin gel. It indicates a high yield value and structural breakdown at low shear rates.

The opposite of thixotropy where the consistency of a material increases with time at constant shear rate.

Caused by the increased collision frequency of dispersed particles or polymer molecules in suspension. This leads to enhanced interparticle bonding and thickening with time.

A material that shows antithixotropy. It thickens with time at constant shear rate, eventually reaching equilibrium.

The state where the up-curve and down-curve of the hysteresis loop overlap in antithixotropic systems. The material exhibits gel-like properties and increased suspendability.

A type of cup-and-bob viscometer where the cup rotates, shearing the sample between the cup and bob.

A type of cup-and-bob viscometer where the bob rotates, shearing the sample between the cup and bob.

The rotating bob experiences viscous drag from the sample. The torque required to rotate the bob is proportional to the viscosity of the sample.

A plot of shear rate (rpm) versus shear stress (weight added) in a cup-and-bob viscometer.

In a Searle type viscometer, the material near the rotating bob flows, but the material near the cup remains stationary as a solid plug.

Plug flow leads to inaccurate viscosity measurements because material doesn't flow uniformly throughout the gap.

Samples with a viscosity between 0.5 and 20,000 poise are best for these types of viscometers.

Use the largest bob possible with a cup of a fixed circumference to minimize the gap between them.

A viscometer that measures viscosity by shearing a sample between a stationary plate and a rotating cone. The speed of the cone can be varied, and the torque (shearing stress) on the cone is measured.

A viscometer that uses a spindle to measure the viscosity of a sample. The spindle rotates at a constant speed, and the torque on the spindle is measured.

A measure of a fluid's resistance to flow under stress. It's the ratio of shear stress to shear rate.

Viscosity divided by density. It measures a fluid's resistance to flow due to gravity.

The ratio of the viscosity of a dispersion to the viscosity of its solvent.

Viscosity changes significantly with temperature. Liquids become less viscous (more fluid) at higher temperatures.

An equation that describes the relationship between viscosity, temperature, and activation energy for flow.