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1) In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure ______________ the vapor pressure of the liquid at the suction temperature? a. Lower than b. Higher than c. Equal to d. None of these
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2) A centrifugal pump is called a turbine pump, if it is having a_________________? a. Turbine type impeller b. Vaned diffusion casing c. Rotating vaned volute d. None of these
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3) The velocity profile exhibited by laminar flow of Newtonian fluids is such that the velocity distribution w.r.t. radius of the circular pipe is a/an ______________ with the apex at the centre line of the pipe? a. Hyperbola b. Parabola c. Semi-circle d. Semi-ellipse
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4) The hydrodynamic and thermal boundary layers will merge, when ____________________? a. Prandtl number is one b. Schmidt number tends to infinity c. Nusselt number tends to infinity d. Archimedes number is greater than 10000
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5) The energy equation, E + (p/ρ) + (V2/2g) + gZ = constant (E = internal energy/mass), is applicable to___________________? a. Perfect gases only b. Isothermal flow of gases c. Adiabatic unsteady flow of gases d. All compressible fluids
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6) A Rotameter works on the principle of _______________ pressure drop? a. Constant b. Variable c. Both A. & B. d. Neither A. nor B.
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7) The equivalent diameter for flow through a rectangular duct of width B and height H is___________________? a. HB/2 (H + B) b. HB/(H + B) c. 2HB/(H + B) d. 4HB/(H + B)
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8) Mass velocity in case of steady flow and through a constant cross-section conduit is independent of the _________________? a. Temperature b. Pressure c. Both A. & B. d. Neither A. nor B.
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9) Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter ‘d’ ? a. At the centre b. At d/4 from the wall c. At the wall d. At d/8 from the wall
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10) Upto what value of ‘Mach number’, a fluid may be considered as incompressible ? a. 0.03 b. 0.3 c. 3 d. 10
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11) Velocity distribution for flow between two fixed parallel plates_________________? a. Varies parabolically across the section b. Is constant over the entire cross-section c. Is zero at the plates and increases linearly to the mid-plane d. None of these
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12) The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost is P. Inlet pressure Q. Compressor rpm R. Delivery pressure S. Volumetric flow rate at inlet ? a. P, Q and R b. P and R c. R and S d. P, Rand S
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13) Differential manometer measures the____________________? a. Atmospheric pressure b. Sub-atmospheric pressure c. Pressure difference between two points d. None of these
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14) Medium viscosity lubricating oil can be most ideally pumped by a ______________ pump? a. Vane b. Piston c. Centrifugal d. Plunger
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15) With increase in temperature, the vapor pressure of liquids__________________? a. Increases b. Increases linearly c. Decreases d. Remain constant
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16) Remote control valve is a _______________ valve? a. Gate b. Butterfly c. Needle d. Globe
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17) Most of the centrifugal pumps used in chemical plants are usually ____________________ driven? a. Steam b. Diesel engine c. Electric motor d. Gas turbine
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18) The uniformity of a gas fluidised bed depends upon the _______________ of the solid particles? a. Size b. Surface properties c. Both A. and B. d. Neither A. nor B.
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19) Permanent loss in a Venturimeter is about ___________ percent of the pressure drop in the upstream cone? a. 1 b. 10 c. 40 d. 70
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20) Mass velocity is independent of temperature & pressure, when the flow is______________________? a. Unsteady through unchanged cross-section b. Steady through changing cross-section c. Steady and the cross-section is unchanged d. Unsteady and the cross-section is changed
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21) Water hammer in a pipeline results from the____________________? a. Bursting of pipelines due to closure by a valve b. Rapid pressure change due to a rapid change in the rate of flow c. Pressure increase due to closure of a valve resulting in decrease in rate of flow d. None of these
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22) Kinetic energy of fluid per unit weight represented by the velocity head is given by___________________? a. 2v2/gc b. v2/2gc c. ρv2/gc d. ρ.v2/2gc
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23) If the discharge of a centrifugal pump is throttled, then its suction lift_______________________? a. Increases b. Decreases c. Remains unchanged d. Data insufficient to predict
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24) With increase in the shear rate, the apparent viscosity of pseudo-plastic fluids__________________? a. Increases b. Decreases c. Remain same d. May increase or decrease; depends on the magnitude of shear rate
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25) A particle A of diameter 10 microns settles in an oil of specific gravity 0.9 and viscosity 10 poise under Stoke’s law. A particle B with diameter 20 microns settling in the same oil will have a settling velocity ? a. Same as that of A b. One fourth as that of A c. Twice as that of A d. Four times as that of A
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26) A piezometer opening measures the _____________ fluid pressure? a. Static b. Undisturbed c. Total d. Dynamic
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27) The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10-6m2/s) ? a. 24000 b. 24 c. 0.24 d. 0.44
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28) For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is___________________? a. More b. Less c. Equal d. Either A. or B.; depends on the viscosity of the fluid
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29) Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be _____________________ ft? a. Maximum theoretical suction lift for water at 15°C by a centrifugal pump is 34 ft. The same for water at 90°C will be _____________________ ft? b. 34 c. 8 d. 37
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30) The terminal velocity of a particle moving through a fluid varies as dp n. The value of n is equal to _______________ in Stoke’s law regime? a. 1 b. 0.5 c. 2 d. 1.5
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31) Which is the correct relationship for a centrifugal pump? (Where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm) ? a. D = 1840 H0.5/N b. D = 1840 N/H0.5 c. H = 1840 D0.5/N d. D = 1840 H/N
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32) Pump used for the transportation of molten sodium in a fast breader reactor is a/an __________ pump? a. Reciprocating b. Plunger c. Electromagnetic d. Gear
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33) Head developed by a centrifugal pump depends on its___________________? a. Speed b. Impeller diameter c. Both A. and B. d. Neither A. nor B.
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34) Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the_______________? a. Back flow of fluid in the event of stoppage of pump b. Discharge pressure c. Flow of liquid during operation of the pump d. All A., B. and C.
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35) At high Reynolds number_________________? a. Inertial forces control and viscous forces are unimportant b. Viscous forces predominate c. Inertial forces are unimportant and viscous forces control d. None of these
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36) Sewage sludge is ______________ type of non-Newtonian fluid? a. Dilatant b. Bingham plastic c. Pseudo plastic d. None of these
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37) Cavitation can be prevented by________________? a. Suitably designing the pump b. Maintaining the suction head sufficiently greater than the vapour pressure c. Maintaining suction head = developed head d. Maintaining suction head lower than the vapour pressure
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38) In fluid flow, cavitation is caused, if the____________________? a. Fluid velocity decreases to zero b. Total energy decreases c. Both A. and B. d. Flow pressure approaches its vapor pressure at the prevailing temperature
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39) For the transfer of solution of thick slurry, the pump used is a _____________ pump? a. Reciprocating b. Gear c. Diaphragm d. Centrifugal
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40) Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is________________? a. 90 b. 60 c. 45 d. 30
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