Fluid Mechanics for Chemical MCQs

Free 744+ Fluid Mechanics for Chemical MCQs for PPSC, FPSC, NTS, and Pakistan government job tests. Practise below with answers and explanations.

744 MCQs available← Back to Fluid Mechanics for Chemical

744 questions in this list. Select an option to practice, or open a question for the full page with explanation.

About this subject

Fluid Mechanics for Chemical

Show Answers

Correct options are highlighted when revealed.

1.Identify the incorrect statement from the following:

Surface tension in liquids arises due to the imbalance between adhesive and cohesive forces.A hydrometer determines the specific gravity of liquids based on the principle of buoyancy.In unsteady fluid flow, the velocity at a specific location remains constant over time.Turbulent flow is distinguished by rapid variations in instantaneous pressure and velocity at a point.

2.Identify the incorrect statement from the following:

When a fluid rotates at a constant angular velocity, it experiences no shear stress.Newton’s viscosity law does not apply to turbulent fluid flow with a linear velocity profile.The lubrication in different kinds of bearings involves laminar flow of viscous fluids.The height to which water rises in capillary tubes decreases as the tube diameter increases.

3.Identify the incorrect statement from the following:

Eddy viscosity depends on the nature of the turbulence present.Eddy viscosity is an inherent property of the fluid.Gas viscosity rises as temperature increases.Liquid viscosity increases when temperature decreases.

4.Which of the following statements about a Venturimeter is accurate?

A Venturimeter with a constant pressure difference allows a higher flow rate when the fluid moves vertically upward.The contraction coefficient of a Venturimeter is always equal to one.For a given pressure drop, gas flow through a Venturimeter is larger when compressibility effects are ignored.None of the above statements are correct.

5.Which of the following statements is accurate?

Human blood behaves as a Newtonian fluid.Newtonian fluids follow Newton’s law of cooling.A graph of shear stress versus shear rate for a non-Newtonian fluid is always a straight line through the origin.Thin lubricating oil is classified as a non-Newtonian fluid.

6.Identify the incorrect statement regarding a streamline.

A streamline is always aligned with the primary flow direction of the fluid.It represents a line where no fluid crosses, acting like a solid boundary.Streamlines can cross only at points where the velocity is either zero or infinite.The fluid confined between two streamlines can be treated as a separate entity, with streamline spacing inversely related to velocity.Streamlines provide a snapshot of fluid flow patterns at a given instant.

7.Identify the incorrect statement from the following options:

Form drag does not rely on the presence of a wake behind the object.In steady flow within a pipe, whether laminar or turbulent, shear stress changes linearly with the radial position.An ideal fluid is characterized by negligible surface tension and follows Newton’s law of viscosity.The presence of a boundary layer in fluid motion is caused by the fluid's viscosity.

8.Identify the incorrect statement from the following options:

The thickness of the boundary layer increases with higher kinematic viscosity of the fluid.Blowers can generate a maximum pressure of up to 2 atmospheres.Losses due to friction in pipe fittings are usually represented using velocity heads.The Fanning friction factor for turbulent liquid flow in pipes depends on relative roughness and Reynolds number.

9.Identify the incorrect statement regarding the flow of an incompressible fluid through a Venturimeter.

In the absence of friction, the pressure at the inlet of the Venturimeter equals the pressure at its outlet.The fluid flow rate through a Venturimeter is determined solely by the pressure difference, regardless of the device's orientation.A Venturimeter requires less installation space compared to an orificemeter.Compared to a similar orificemeter, a Venturimeter results in lower energy loss.

10.Which of the following statements about a Venturimeter is accurate?

The flow rate through a Venturimeter depends solely on the pressure difference (Δp) and is unaffected by the meter’s orientation.For a fixed gauge pressure difference, a Venturimeter allows a higher flow rate when the fluid moves vertically downward compared to vertically upward.Given the same pressure difference, gas flow through a Venturimeter is higher when compressibility effects are considered than when they are ignored.The total pressure drop in a pipeline remains identical whether a Venturimeter or a nozzle with the same throat diameter is installed.None of the above statements are correct.

11.Identify the incorrect statement from the following options:

In laminar flow, momentum transfer occurs due to the velocity gradient.A fluid at rest in equilibrium can still experience shear stress.The viscosity of a non-Newtonian fluid depends solely on temperature.Both statements B and C are incorrect.

12.Which of the following statements is true?

A forced vortex is formed when the fluid rotates like a solid body around a central axis.Newton's viscosity law is invalid in laminar flow conditions.A free vortex is characterized by fluid rotating as a solid mass.Turbulent flow lacks any cross-currents or swirling eddies.

13.Identify the incorrect statement from the following options:

At a specific point within a stationary liquid, the pressure is identical regardless of the type of liquid.In an isothermal atmosphere, pressure drops exponentially as altitude increases.Atmospheric pressure equals absolute pressure minus gauge pressure.According to Pascal's law, pressure at a point in a fluid at rest or moving uniformly is the same in every direction.

14.Which of the following statements about the flow in a converging-diverging nozzle is accurate?

The Mach number is invariably equal to one at the nozzle's narrowest section.A shock wave does not form inside the nozzle if the exit Mach number exceeds one.The density consistently rises along the flow direction in the converging section of the nozzle.None of the above statements are true.

15.Identify the incorrect statement from the following options:

For laminar flow of a Newtonian fluid in a pipe with diameter D and length L, the shear stress at the pipe wall is given by (D/4L) × Δp.In the relation T · gc = k · (du/dy)^n, the exponent 'n' equals 1 for pseudoplastic fluids and dilatant fluids respectively.The shear stress in a Newtonian fluid is directly proportional to the velocity gradient perpendicular to the flow direction.When the Mach number exceeds 0.6, the drag coefficient for compressible fluids tends to decrease.

16.Identify the incorrect statement from the following:

Vacuum pressure is always represented as a negative gauge pressure.The pressure indicated by a piezometer tube corresponds to the gauge pressure of the liquid.Manometric fluids must possess high surface tension.The point where the resultant force acts on a submerged surface is called the center of pressure.

17.Which of the following statements is true?

The Fanning friction factor is always inversely related to the Reynolds number.The characteristic of a randomly packed bed containing Raschig rings is defined by the ratio of total volume to void volume.For incompressible fluids, the Mach number is consistently equal to one.Mach number is defined as the ratio between the fluid velocity and the speed of sound within the fluid.

18.Identify the incorrect statement regarding cavitation.

Cavitation occurs due to a sudden drop in pressure caused by flow separation, vortex creation, or the rapid closing of a valve.Cavitation can happen when liquid boils because of a pressure decrease, leading to vapor bubble formation.Cavitation initiates at relatively higher static pressures and lower velocities in pipelines with larger diameters.Extensive cavitation cannot cause damage to pipelines, obstruct fluid flow, or harm steam turbine blades.Cavitation involves the formation and collapse of vapor bubbles within a fluid.

19.For which of the following situations is a globe valve best suited?

Precise regulation of fluid flow is neededThe fluid includes suspended solid particlesThe valve must operate only in fully open or fully closed positionsFlow is intended to move in a single direction

20.According to the Buckingham π theorem, in a physical problem involving 'n' variables with 'm' fundamental dimensions, how many independent dimensionless groups can be formed?