Practice Questions

Surface tension is the property of a liquid that causes its free surface to behave like an elastic stretched membrane. A small liquid drop takes a spherical shape due to the minimum surface area for a given volume, caused by surface tension. Applications of surface tension include capillary action, which draws ink to the tips of fountain pen nibs, and the warm soup tastes tasty as its surface tension is low at high temperatures

To allow flow between two points in a pipeline, the differential pressure between them must be greater than surface friction, viscosity force, and frictional force. This is because the pressure force of the fluid needs to overcome these resistances.

Viscosity is the resistance to the motion of fluid layers. In liquids, the cohesive force causes viscosity, which decreases with temperature as molecules move away from each other. In gases, viscosity is caused by molecular randomness, which increases with temperature, causing viscosity to increase. Pressure has no effect on viscosity.

In general, it decreases with temperature for liquids because the internal force of attraction between two fluid layers gets decreased.

In general, it decreases with temperature for gases because the internal force of attraction between two fluid layers gets decreased.

In general, it increases with temperature for liquids because the internal force of attraction between two fluid layers gets increased.

In general, it increases with temperature for gases because the internal force of attraction between two fluid layers gets increased

A fluid at rest cannot resist shear stress and any applied shear stress, no matter how small, will result in the motion and the fluid. Thus the shear zero for a fluid at rest.

The shear stress is zero only on the horizontal plane

The shear stress in maximum on a place inclined at 45° to the horizontal

The shear stress depends upon the co-efficient of viscosity

Density is defined as mass divided by volume, represented by the equation p = m/V. The CGS unit of mass density is g/cm³.

Differential manometers measure the pressure difference between two points. They are commonly used in pipes or channels. The U-tube differential manometer is the most common type, consisting of a U-tube filled with heavy liquid. The equation for pressure difference is ΔP = pgh, where p is the density of the liquid, g is acceleration due to gravity, and h is the height difference of the liquid in the U-tube.

Difference of pressure between two points

Redwood viscometer determines the absolute value of viscosity by measuring the time taken for a fixed volume of fluid to flow through an orifice at a specific temperature. The frictional force between the fluid and the orifice determines the viscosity.

Absolute value of viscosity is determined

Part of the head of fluid is utilised in overcoming friction

Fluid discharges through orifice with negligible velocity

20. Newton's law of viscosity relates shear stress and the rate of shear strain. It is given by the equation r = μ (du/dy)

shear stress and the rate of angular distortion

Viscosity is the measure of a fluid's resistance to deformation caused by friction within the fluid. There are two kinds of viscosity: Dynamic viscosity (μ) and Kinematic viscosity (v). Dynamic viscosity is measured in $Ns / m ^ 2$ or Pa - s or Poise, while kinematic viscosity is measured in $m ^ 2 / s$ or Stokes.

The definition of the compressible and incompressible fluid is defined according to the changes in density. Compressible fluids are fluids whose density can change significantly with changes in pressure or temperature. Incompressible fluids, on the other hand, are fluids whose density remains relatively constant with changes in pressure or temperature.

Water is a Newtonian fluid because its shear stress is linearly proportional to its shear strain rate.

Viscosity is the internal resistance of a fluid to motion. The unit of dynamic viscosity is $N. s / m ^ 2$ . Kinematic viscosity is the ratio of dynamic viscosity to density and its unit is Stoke or  $m ^ 2 / s$

Mass density represents the mass (or the number of particles) per unit volume of a substance, material, orobject. Mass density is also known as density.its SI unit is $kg/m^3$

Kinematic viscosity is the ratio of dynamic viscosity to mass density. The equation for kinematic viscosity is v = μ/ρ. Its Sl unit is m²/s and CGS unit is cm²/s or stoke.

When a fluid is at rest, it does not resist shear stress as a solid does. Any amount of shear stress applied to a fluid will cause it to move and deform continuously. Therefore, a fluid at rest must be in a state of zero shear stress.

6. hear thickening fluid, also known as Dilatant, is a type of fluid whose viscosity increases as the shear rate increases. This is in contrast to shear thinning fluids, which have a decreasing viscosity as shear rate increases.

4. Dynamic viscosity is the property of a fluid that offers resistance to the movement of one layer of fluid over an adjacent layer of the fluid. Poise is a unit of dynamic viscosity, where 1 Poise is equivalent to 0.1 N s/m2. 1 Poiseuille is equivalent to 10 Poise and 1 decapoise.

aper pulp is a type of non-Newtonian fluid known as a pseudoplastic fluid. Other examples of pseudoplastic fluids include fine particle suspensions, gelatine, blood, and polymeric solutions such as rubbers and paints. Pseudoplastic fluids have a decreasing viscosity with increasing shear rate.

Mercury does not wet the glass because of the property of the liquid known as cohesion. Cohesion refers to the attractive force between molecules of the same substance, which in the case of mercury, is stronger than the adhesive forces between mercury and glass.

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