chemical engineering fluid mechanics for chemical chemical engineering MCQs – Page 30

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 Review each marked answer and report any item that may be outdated or unclear.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
581. Which of the following fluid forces are not considered in the Navier-Stokes equation ?
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A. Viscous forces

B. Pressure forces

C. Turbulent forces

D. Gravity forces

582. Which of the following factors does not contribute to the pressure drop in a pipeline ?
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A. None of these

B. Size of pipe

C. Velocity of fluid

D. Length of pipe and number of bends

583. Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the leading edge.) ?
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A. d2/3

B. d1/3

C. ?d

D. d4/5
584. Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the___________________?
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A. All A., B. and C.

B. Fluid velocity in the pipe

C. Pipe length

D. Time taken to close the valve

585. A fluid is pumped at the rate of 10 lb/sec to a height of 55 ft. The horse power required is _____________ hp?
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A. 5.5

B. Oct-55

C. Jan-55

D. 1
586. While starting a centrifugal pump, its delivery valve should be kept___________________?
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A. Either opened or closed; depending on the fluid viscosity

B. Either opened or closed; it does not make any difference

C. Opened

D. Closed
587. The fluid property which matters for falling rain drops to acquire spherical shape is its__________________?
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A. Viscosity

B. Surface tension

C. Height of descend

D. Pressure

588. Draining of shallow pits or sump is done by a sump pump, which is a ______________ pump?
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A. Centrifugal

B. Single stage vertical

C. Plunger

D. Diffuser

589. Characteristic curves for a centrifugal pump plotted against its capacity is shown in the diagram. x, y and z denote respectively_______________?
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A. Head, efficiency and B.H.P.

B. Efficiency, head and B.H.P.

C. B.H.P., efficiency and head

D. Efficiency, B.H.P. and head

590. The pressure at a point in a fluid is not the same in all directions, when the fluid is viscous and___________________?
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A. Hot

B. Static

C. Moving

D. Cold

591. Choking in case of pipe flow means that a___________________?
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A. None of these

B. Valve is closed in the line

C. Restriction in flow cross-section area occurs

D. Specified mass flow rate cannot be achieved
592. Steady fluid flow occurs, when the derivative of flow variables satisfy the following condition.
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A. ?/?t = 0

B. ?/?t = constant

C. ?/?s = 0

D. ?/?s = constant

593. The specific speed of a pump is defined as the speed of a unit of such a size, that it__________________?
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A. Delivers unit discharge at unit power

B. Delivers unit discharge at unit head

C. None of these

D. Requires unit power for unit head

594. Buoyant force__________________?
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A. For non-symmetrical bodies is not vertical

B. Depends on the depth of the submergence of the floating body

C. Depends on the weight of the floating body

D. None of these

595. In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of___________________?
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A. Friction co-efficient for flows at equal Reynold number

B. All A., B. & C.

C. Absolute roughness

D. Relative roughness

596. The flow of a liquid through tapering pipe at a constant rate is an example of _______________ flow?
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A. Steady uniform

B. Steady non uniform

C. Unsteady non uniform

D. Unsteady uniform

597. A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is__________________?
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A. 5 ?2 m/sec

B. 5 m/sec

C. 10 m/sec

D. 20 m/sec

598. Capacity of a hydraulic accumulator is defined in terms of maximum_____________________?
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A. Amount of energy stored

B. Rate of falling of ram

C. Volume available in the cylinder

D. Flow rate through accumulator

599. The terminal velocity of a particle moving through a fluid varies as dp n. What is the value of n for Newtons law regime ?
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A. 0.5

B. 1.5

C. 1

D. 3

600. Priming of a centrifugal pump is done to___________________?
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A. None of these

B. Develop effective pressure rise by the pump

C. Increase the mass flow rate of fluid

D. Avoid chances of separation inside the impeller