0% 0 Fluid Mechanics for Chemical Quiz 3 1 / 50 Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation ? Decrease in effect Increase in thrust Develops high pressure Develops noise 2 / 50 Centrifugal compressors compared to reciprocating compressors___________? All A., B. and C. Have lower operating costs Have quieter operation Require less space 3 / 50 Check valve is used for _________ flow? None of these Multidirectional Unidirectional Very precise control of 4 / 50 Cavitation occurs in a centrifugal pump when the suction pressure is_________? Equal to the developed head Less than the vapour pressure of the liquid at that temperature Equal to the vapour pressure Greater than the vapour pressure of the liquid at that temperature 5 / 50 Consider a centrifugal pump having a specific impeller diameter, fixed impeller speed pumping a liquid of constant density at a particular discharge capacity. With decrease in the capacity of the pump, the ________ decreases? Head of the liquid pumped BHP required by the pump NPSH required All A., B. and C. 6 / 50 Capillary rise of mercury in a small diameter tube is proportional to (where, d = diameter of the tube, ? = surface tension of mercury)______? 1/d 1/? d ? 7 / 50 Creeping flow around a sphere is defined, when particle Reynolds number is_____? < 2100 < 500 < 0.1 > 2.5 8 / 50 Capillary tube method of viscosity measurement is based on the _________? Hagen-Poiseuille?s equation None of these Navier-stokes equation Stoke?s law 9 / 50 Buckingham-? theorem states that in any physical problem including ?n? quantities having ?m? dimensions, the quantities can be arranged into ______ independent dimensionless parameters? n-m n m n/m 10 / 50 Buoyant force___________? Depends on the weight of the floating body For non-symmetrical bodies is not vertical None of these Depends on the depth of the submergence of the floating body 11 / 50 Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f1 and that for smooth pipe is f2. Pick out the correct statement ? f1 < f2 f1 = f2 f1 > f2 Data not sufficient to relate f1 & f2 12 / 50 Centrifugal pump is normally classified on the basis of the_________? rpm Impeller blade angle Number of blades in impeller Type of casing 13 / 50 Boundary layer separation occurs when the______? Velocity of sound is reached Pressure reaches a minimum Valve is closed in a pipeline Cross-section of the channel is reduced 14 / 50 Design of the casing of centrifugal pump should be such as to minimise the_________? None of these Loss of static head Loss of kinetic head Back flow through impeller 15 / 50 Cavitation in a centrifugal pump can be avoided by keeping the___________? Outlet pressure high Inlet pressure high Inlet pressure low Outlet pressure low 16 / 50 Co-efficient of velocity is _____ the coefficient of discharge? Equal to Less than Not related to More than 17 / 50 Co-efficient of discharge (Cd) is defined as actual discharge/theoretical discharge and is equal to Cc . Cv; where Cc = Co-efficient of contraction and Cv = co-efficient of velocity. Cd of an orifice is usually about___________? 0.82 0.98 0.42 0.62 18 / 50 Dean number is concerned with the______? Fluid-particle interaction Fluid flow through helical pipes Psychrometry Power consumption in agitated vessels 19 / 50 Centrifugal pumps as compared to reciprocating pumps___________? Run at a lower speed for the same discharge Can be run with discharge line valve closed for a short interval Deliver fluid with pulsating/fluctuating discharge Do not need priming 20 / 50 Cd is always _______ Cc? Less than Equal to Either more or less than Greater than 21 / 50 Colebrook equation for friction factor in turbulent flow is given by, f-0.5 = -4 loge [(?/D) + (1.26/NRe ?F). It reduces to Nikuradse equation for a value of (?/D) equal to ___________? ? 0.5 0 1 22 / 50 Choking in case of pipe flow means that a_____? None of these Valve is closed in the line Specified mass flow rate cannot be achieved Restriction in flow cross-section area occurs 23 / 50 Check valves are used________? In bends For controlling water flow At high pressure For unidirectional flow 24 / 50 Dimension of kinematic viscosity is_______? L2T-2 MLT-1 L2T L2T-1 25 / 50 Differential manometer measures the______? Pressure difference between two points Sub-atmospheric pressure None of these Atmospheric pressure 26 / 50 Choose the set of pressure intensities that are equivalent ? 10 psi, 19.7 ft. of water, 23.3 inches of Hg 10 psi, 19.7 ft. of water, 5.3 inches of Hg 4.33 psi, 10 ft. of water, 8.83 inches of Hg 4.33 psi, 10 ft. of water, 20.7 inches of Hg 27 / 50 Curve III in the bellow diagram represents a/an_________? Pseudo plastic fluid None of these Dilatent fluid Ideal plastic 28 / 50 Diaphragm valves are used for handling ________ fluids? Corrosive Solid suspended Non-Newtonian Viscous 29 / 50 Cavitation can be prevented by_________? Maintaining suction head lower than the vapour pressure Maintaining suction head = developed head Suitably designing the pump Maintaining the suction head sufficiently greater than the vapour pressure 30 / 50 Disc compensators are provided in large diameter fuel gas carrying pipelines to__________? Account for the pressure variation side the pipeline Make the pipe joint leak-proof Keep the pipe in proper orientation Account for contraction/expansion of pipe due to temperature changes of the surroundings 31 / 50 Brownian movement is prominent in the particle size range of ______ microns in case of settling of a particle in a fluid? 200 to 300 100 to 1000 0.01 to 0.10 2 to 3 32 / 50 Diaphragm pumps are used to transport__________? Fluids Slurries Liquids Solids 33 / 50 Deformation drag, which is caused by widespread deformation of fluid around the immersed body______? Is independent of body length Is primarily a friction drag Occurs when NRe is very small Depends mainly on cross-sectional shape 34 / 50 Centrifugal pump can?t be used to pump _______? Thick molten soap at 80?C Molten sodium (used as a coolant in Fast Breeder Reactor) None of the above Moderately viscous vegetable oil used in soap industry 35 / 50 Check in a centrifugal pump is_________? Provided to prevent liquid from backing up through the pump when the pump is turned off or accidently stops running Provided in the discharge line All A., B. and C. Generally a globe valve 36 / 50 Check valve provided in the discharge line of a centrifugal pump serves the purpose of controlling the________? Back flow of fluid in the event of stoppage of pump All A., B. and C. Flow of liquid during operation of the pump Discharge pressure 37 / 50 Boundary layer thickness in turbulent flow over a flat plate increases as(where, d = distance from the leading edge.) ? ?d d4/5 d1/3 d2/3 38 / 50 Cp/Cv is termed as___________? Mach number Adiabatic constant Weber number Prandtl number 39 / 50 Dimension of surface tension is (where, F = force, L = length) ? F-2. L FL-1 F-1. L F.L-2 40 / 50 Critical velocity in a pipe flow__________? Independent of fluid density None of these Increases as fluid viscosity increases Increases as pipe diameter increases 41 / 50 Capacity of a hydraulic accumulator is defined in terms of maximum_______? Amount of energy stored Volume available in the cylinder Rate of falling of ram Flow rate through accumulator 42 / 50 Cocks are used to control _____? Water None of these Solids Any liquid 43 / 50 Centre of pressure in an immersed body is _______ the centre of gravity? Above At Either above or below; depends on the liquid density Below 44 / 50 Boundary layer thickness in laminar flow over a flat plate increases as(where, d = distance from the leading edge.) ? d1/3 d2 d2/3 ?d 45 / 50 Choose the correct set of dimensions of viscosity that are equivalent (where, F, M, L, T are dimensions for force, mass, length and time respectively) ? FL-2T, ML-1T-1 ML-1T-3, F-1L2T F-1L2T-1, MLT-3 FLT, ML-1T-1 46 / 50 Dimension of absolute viscosity is__________? ML-1T-1 MLT ML-1T MLT-1 47 / 50 Cd for the orifice plate varies from _____? 0.58 to 0.8 0.93 to 0.98 0.02 to 0.03 0.2 to 0.3 48 / 50 Differential manometer measures the_____? Pressure difference Pressure gradient Absolute pressure Gauge pressure 49 / 50 Centre of pressure of a plane surface of arbitrary shape immersed vertically in a static mass of fluid_________? Is independent of the specific weight of the fluid Lies above the centroid of the plane surface Is at the centroid of the plane surface Is different for different fluids 50 / 50 Capacity of a rotary gear pump can be varied by___________? Bleeding air into suction Changing the speed of rotation Bypassing liquid from the suction or discharge line All A., B. and C. Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevFluid Mechanics for Chemical Quiz 2 Fluid Mechanics for Chemical Quiz 4Next
