chemical engineering fluid mechanics for chemical chemical engineering MCQs – Page 15

Practise multiple-choice questions from chemical engineering fluid mechanics for chemical chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering fluid mechanics for chemical chemical engineering Mcqs
701. What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition ?
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A. 0.5

B. 1

C. 2

D. 0.67

702. The equivalent diameter for pressure drop calculation for a fluid flowing through a rectangular cross-section channels having sides x & y is given by_________________?
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A. xy/(x + y)

B. 2xy/(x + y)

C. (x + y)/xy

D. (x + y)/2xy

703. Specific speed for a centrifugal pump is___________________?
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A. N ?Q/H

B. N ?Q/H3/4

C. N3D5/H1/3

D. N ?Q/H2/3

704. Rubber latex is an example of a ______________ fluid?
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A. Dilatent

B. Bingham plastic

C. Pseudo plastic

D. Newtonian

705. Which is not a variable head meter _________________?
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A. None of these

B. Pitot tube

C. Rotameter

D. Venturimeter

706. For laminar flow through a closed conduit____________________?
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A. Vmax = Vav

B. Vmax = 0.5Vav

C. Vmax = 2Vav

D. Vmax = 1.5Vav

707. Creeping flow around a sphere is defined, when particle Reynolds number is___________________?
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A. < 2100

B. < 500

C. > 2.5

D. < 0.1
708. In the low Reynolds number region, the drag force on a sphere is proportional to_______________?
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A. V0.5

B. V2

C. V4

D. V
709. The continuity equation___________________?
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A. None of these

B. Represents the conservation of mass

C. Is dependent upon the viscosity of the fluid

D. Is independent of the compressibility of the fluid

710. The most economical flow control valve for use with large diameter pipes is a__________________?
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A. Butterfly valve

B. Globe valve

C. None of these

D. Needle valve

711. Buckingham-? theorem states that in any physical problem including n quantities having m dimensions, the quantities can be arranged into _____________ independent dimensionless parameters?
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A. m

B. n

C. n/m

D. n-m
712. Pick out the correct statement?
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A. The property of a randomly packed bed (with raschig rings) is given by the ratio of the total

B. ume to the volume of voids in the bed

C. Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under

D. Mach number in an incompressible fluid is always unity

E. Fanning friction factor is inversely proportional to Reynolds number always

F. ditions of flow</strong>

713. Venturimeter and orificemeter measures the _____________ of the fluid?
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A. Maximum velocity

B. Point velocity

C. Average velocity

D. Pressure

714. For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is________________?
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A. Equal

B. Less

C. More

D. Independent of porosity

715. Foot valve provided in the pump is a ______________ valve?
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A. Relief

B. Direction control

C. Pressure reduction

D. Back pressure
716. At low Reynolds number______________?
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A. Viscous forces are unimportant

B. Gravity forces control

C. Viscous forces control and inertial forces are unimportant

D. Viscous forces control

717. Which of the following is an undesirable property of a manometric liquid ?
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A. Low viscosity & surface tension

B. High vapour pressure

C. Low co-efficient of thermal expansion

D. Non-sticky & non-corrosive nature

718. The maximum head that can be developed by a single impeller is _____________ ft?
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A. 100

B. 1000

C. 250-300

D. 25

719. In frictional fluid flow, the quantity, (P/?) + (V2/2gc) + gz/gc) is___________________?
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A. Increased in the direction of flow

B. Not constant along a streamline

C. Constant along a streamline

D. None of these

720. An equipotential line is _____________ to the velocity vector at every point?
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A. Normal

B. None of these

C. Tangential

D. Parallel

721. The fluid jet discharging from a 2? diameter orifice has a diameter of 1.75? at its venacontracta. The co-efficient of contraction is___________________?
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A. None of these

B. 0.87

C. 0.766

D. 1.3

722. The hydraulic diameter of an annulus of inner and outer radii Ri and Ro respectively is___________________?
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A. Ro + Ri

B. 4(Ro-Ri)

C. ?(Ro-Ri)

D. 2(Ro-Ri)
723. Pick out the wrong statement ?
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A. ces

B. Turbulent fluid flow is characterised by the rapid fluctuation of instantaneous pressure &

C. buoyant forces

D. A hydrometer used for the determination of specific gravities of liquids works on the principle

E. ocity at a point

F. Surface tension of a liquid is because of the difference in magnitude of adhesive & cohesive

724. When the head pumped against is less than the head of the fluid used for pumping, the usual device is a/an______________________?
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A. Ejector

B. Injector

C. Blower

D. Airlift
725. Pick out the wrong statement about a streamline ?
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A. It is always parallel to the main direction of the fluid flow

B. It is a line across which there is no flow and it is equivalent to a rigid boundary

C. The fluid lying between any two streamlines can be considered to be in isolation and the

D. Streamlines intersect at isolated point of zero velocity and infinite velocity

E. eamline spacing varies inversely as the velocity

726. The nominal size of a hose pipe is specified by its _________________?
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A. O.D.

B. I.D.

C. None of these

D. Thickness

727. Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of ______________ pressure?
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A. Gage

B. Absolute

C. Small differential

D. Atmospheric

728. Minimum fluidisation velocity for a specific system depends upon the___________________?
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A. Particle size

B. Fluid viscosity

C. Density of both the particle & the fluid

D. All A., B. and C.
729. Bernoullis equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoullis equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent. D. Fluid is compressible. E. Fluid is incompressible ?
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A. A, B, E

B. A, D, E

C. B, D, E

D. A, C, D

730. Pick out the wrong statement?
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A. A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocity

B. Rise of water in capillary tubes reduces with the increasing diameter of capillary tubes

C. tribution</strong>

D. Newtons law of viscosity is not applicable to the turbulent flow of fluid with linear velocity

E. Laminar flow of viscous liquids is involved in the lubrication of various types of bearings

731. For flow past a flat plate, if x? is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to________________?
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A. x

B. 1/?x

C. ?x

D. 1/x

732. A pipe has a porous section of length L as shown in the figure. Velocity at the start of this section of V0. If fluid leaks into the pipe through the porous section at a volumetric rate per unit area q(x/L)2, what will be axial velocity in the pipe at any x?? Assume incompressible one dimensional flow i.e., no gradients in the radial direction ?
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A. VX = V0 + ?q (x3/L2)

B. VX = V0 + q (x3/L2D)

C. VX = V0 + (4/3) q (x3/L2D)

D. VX = V0 + 2q (x2/LD)

733. Pick out the correct statement?
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A. A forced vortex occurs when fluid rotates as a solid about an axis

B. A free vortex occurs, when fluid rotates as a solid

C. In laminar flow, Newtons law of viscosity does not apply

D. In turbulent flow, there are neither cross-currents nor eddies

734. N. second/m2 is___________________?
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A. The S.I. unit of dynamic viscosity

B. Equivalent to one stoke

C. Equivalent to one poise

D. The S.I. unit of kinematic viscosity

735. Pick out the wrong statement?
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A. The viscosity of a liquid increases with decrease in temperature

B. The viscosity of gas increases with increase in temperature

C. The eddy viscosity is a function of the type of turbulence involved

D. The eddy viscosity is a fluid property
736. Pick out the wrong statement?
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A. Friction losses in pipe fittings are generally expressed in terms of velocity heads

B. Fanning friction factor in case of turbulent flow of liquids in pipe depends upon relative

C. Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer

D. ghness & Reynolds number

E. Blowers develop a maximum pressure of 2 atmospheres

737. A Newtonian liquid (? = density, ? = viscosity) is flowing with velocity v? in a tube of diameter D. Let ?p be the pressure drop across the length L. For a laminar flow, ?p is proportional to_________________?
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A. D?v2/L

B. L?V/D2

C. L?v2/D

D. ?V/L

738. Unit of mass velocity is__________________?
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A. kg/m2. hr

B. kg/hr

C. kg/m3. hr

D. kg/m2

739. Which of the following produces maximum pressure difference for transportation of gases ?
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A. Vacuum pumps

B. Blowers

C. Fans

D. Compressors
740. Nominal Pipe Size (NPS) of a pipe less than 12 inches in diameter indicates its________________?
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A. Inner diameter

B. Outer diameter

C. Neither inner nor outer diameter

D. Thickness

741. Capillary tube method of viscosity measurement is based on the ________________?
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A. None of these

B. Navier-stokes equation

C. Hagen-Poiseuilles equation

D. Stokes law

742. Bernoullis equation is dependent on the__________________?
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A. Third law of thermodynamics

B. None of these

C. Law of conservation of momentum

D. First law of thermodynamics

743. A hydraulic ram acts as a/an ______________ pump?
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A. Centrifugal

B. Reciprocating

C. Parallel cylinder

D. Impulse
744. Air vessel provided in a reciprocating pump is for__________________?
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A. Increasing the acceleration head

B. Decreasing the acceleration head

C. None of these

D. Making the friction in pipe uniform