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