Description : Drag co-efficient for motion of spherical particles in a stationary fluid in the stoke's law range is (A) 24/NRe,P (B) 16/NRe,P (C) 64/NRe,P (D) 48/NRe,P
Last Answer : (A) 24/NRe,P
Description : In Newton's law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is (A) 0.44 (B) 0.044 (C) 4.4 (D) 44
Last Answer : (A) 0.44
Description : For motion of spherical particles in a stationary fluid, the drag coefficient in hindered settling compared to that in free settling is (A) More (B) Less (C) Equal (D) More or less, depending on the type of particle
Last Answer : (A) More
Description : The terminal velocity of a solid spherical particle falling through a stationary fluid mass in the Stoke's law range is proportional to the (A) Inverse of fluid viscosity (B) Square of particle size (C) Difference in the densities of the particle & fluid (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The ratio of wall drag to total drag in the Stoke's law range is (A) 0.5 (B) 1 (C) 1/3 (D) 2/3
Last Answer : (D) 2/3
Description : In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the __________ of its diameter. (A) Inverse (B) Square root (C) Second power (D) First power
Last Answer : (B) Square root
Description : In the Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is __________ the fluid viscosity. (A) Directly proportional to (B) Inversely proportional to (C) Inversely proportional to the square root of (D) Independent of
Last Answer : (B) Inversely proportional to
Description : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Description : Pick out the wrong statement. (A) The shear stress at the pipe (dia = D, length = L) wall in case of laminar flow of Newtonian fluids is (D/4L). ∆p (B) In the equation, T. gc = k. ... to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids
Last Answer : (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids
Description : __________ forces act on a particle moving through a stationary fluid (A) Gravity (B) Drag (C) Buoyant (D) All (A), (B), & (C)
Last Answer : (D) All (A), (B), & (C)
Description : 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
Last Answer : (C) 2
Description : Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian ... at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows
Last Answer : (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s
Last Answer : (B) 16 mm/s
Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8
Last Answer : (C) 0.7
Description : For the Stoke's law to be valid in the case of a falling sphere in a fluid, the (A) Reynolds number (based on sphere diameter) should be < 1 (B) Flow around the sphere should be in turbulent region (C) Sphere must be metallic (D) Fluid density should be constant
Last Answer : (C) Sphere must be metallic
Description : If G is the specific gravity of particles of diameter d, the velocity of settlement V in still water at T°C, according to Stoke's law, is (A) V = 418 (G - 1) d² [(3T + 70)/100] (B) V = 418 (G - 1) d [(3T - ... 1) d² [(2T + 70)/100] (D) V = 418 (G - 1) d 4 [(3T + 70)/100]
Last Answer : (A) V = 418 (G - 1) d² [(3T + 70)/100]
Description : Pick out the wrong statement. (A) The form drag is dependent upon the occurrence of a wake (B) The shear stress at any given cross-section of a pipe for steady flow (either laminar or turbulent ... of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid
Last Answer : (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity
Description : What is the force required (in Newtons) to hold a spherical balloon stationary in water at a depth of H from the air-water interface? The balloon is of radius 0.1 m and is filled with air. (A) 4πg/3 (B) 0.01 πgH/4 (C) 0.01 πgH/8 (D) 0.04 πgH/3
Last Answer : (A) 4πg/3
Description : Stoke's equation is valid in the Reynolds number range (A) 0.01 to 0.1 (B) 0.1 to 2 (C) 2 to 10 (D) 10 to 100
Last Answer : (A) 0.01 to 0.1
Description : A spherical particle is falling slow in a viscous liquid such that Reynolds number is less than 1. Which statement is correct for this situation? (A) Inertial and drag forces are important (B) Drag ... forces are important (C) Drag force and gravitational forces are important (D) None of the above
Last Answer : (B) Drag, gravitational and buoyancy forces are important
Description : Navier-Stokes equation is useful in the analysis of __________ fluid flow problems. (A) Non-viscous (B) Viscous (C) Turbulent (D) Rotational
Last Answer : (B) Viscous
Description : _________ fluid force is not considered in the Navier-Stokes equation. (A) Turbulent (B) Viscous (C) Gravity (D) Pressure
Last Answer : (A) Turbulent
Description : Which of the following statements are TRUE for damped vibrations? (P) . For a system having critical damping, the value of the damping ratio is unity and system does not undergo a vibratory motion. (Q) . Logarithmic decrement method ... Q only (B) P and S only (C) P, Q and R only (D) Q and S only
Last Answer : (C) P, Q and R only
Description : 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 20microns settling in the same oil will have a settling velocity (A) ... ) One fourth as that of A (C) Twice as that of A (D) Four times as that of A
Last Answer : (B) One fourth as that of A
Description : The passengers standing in a bus fall in the backward direction when the stationary bus begins to move. Which of the following laws explains this situation? (1) Newton's First Law of Motion (2) Newton's Third Law of Motion (3) Newton's Second Law of Motion (4) The Law of Conservation of Momentum
Last Answer : (1) Newton's First Law of Motion Explanation: According to Newton's first law of motion (law of inertia) a body either at rest or in uniform motion will remain so unless acted on by a force When the passengers are standing on the bus, they (and the bus) are in a state of uniform motion.
Description : A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is (A) 0.90 μm/s (B) 1 μm/s (C) 22.1 μm/s (D) 0.02 μm/s
Last Answer : (B) 1 μm/s
Description : Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles ... (A) Drag on particles (B) Drag on column walls (C) Bed height (D) Bed voidage
Last Answer : (C) Bed height
Description : The fluid forces considered in the Navier Stokes equation are (A) Gravity, pressure and viscous (B) Gravity, pressure and turbulent (C) Pressure, viscous and turbulent (D) Gravity, viscous and turbulent
Last Answer : Answer: Option A
Description : The random motion of particles suspended in a fluid is called: w) Boson Condensation x) Fermi Motion y) Brownian Motion z) Pauli Motion
Last Answer : ANSWER: Y -- BROWNIAN MOTION
Description : In fluid flow, the boundary layer separation cannot occur (A) In case of boundaries experiencing form drag (B) At points of abrupt changes in the flow directions (C) In laminar flow (D) None of theseIn ... B) At points of abrupt changes in the flow directions (C) In laminar flow (D) None of these
Last Answer : (D) None of these
Description : Stoke's law is valid, when the particle Reynolds number is (A) < 1 (B) > 1 (C) < 5 (D) None of these
Last Answer : (A) < 1
Description : For the free settling of a spherical particle through a fluid, the slope of, CD-log NRe , plot is (A) 1 (B) -1 (C) 0.5 (D) -0.5
Last Answer : (B) -1
Description : Gage pressure within a spherical droplet of a fluid is 'p'. What will be gage pressure within a bubble of the same size & of the same fluid? (A) p (B) 2 p (C) 0.5 p (D) 0.25 p
Last Answer : (B) 2 p
Description : Stoke's law does not hold good if the size of particle is smaller than (A) 0.0002 mm (B) 0.002 mm (C) 0.02 mm (D) 0.2 mm
Last Answer : (A) 0.0002 mm
Description : Stoke's law is valid only if the size of particle is (A) Less than 0.0002 mm (B) Greater than 0.2 mm (C) Between 0.2 mm and 0.0002 mm (D) All of the above
Last Answer : Answer: Option C
Description : Capillary tube method of viscosity measurement is based on the (A) Hagen-Poiseuille’s equation (B) Stoke's law (C) Navier-stokes equation (D) None of these
Last Answer : (A) Hagen-Poiseuille’s equation
Description : The Navier-Stokes equation deals with the law of conservation of (A) Mass (B) Energy (C) Both (A) & (B) (D) Momentum
Last Answer : (D) Momentum
Description : Stoke's law is valid, when NRe, p is less than (A) 2 (B) 100 (C) 2100 (D) 700
Last Answer : (A) 2
Description : Deformation drag, which is caused by widespread deformation of fluid around the immersed body (A) Occurs when NRe is very small (B) Is primarily a friction drag (C) Is independent of body length (D) Depends mainly on cross-sectional shape
Last Answer : (A) Occurs when NRe is very small
Description : The co-efficient of drag and lift for an incompressible fluid depends on the (A) Reynolds number (B) Froude number (C) Mach number (D) All (A), (B) and (C)
Last Answer : (A) Reynolds numbe
Description : Which of the following is not concerned with the fluid-particle interaction? (A) Drag co-efficient (B) Froude number (C) Galileo number (D) Weber number
Last Answer : (D) Weber number
Description : Drag force acting on a body does not depend upon the (A) Density of the fluid (B) Density of the body (C) Velocity of the body (D) Projected area of the body
Last Answer : (B) Density of the body
Description : Drag is defined as the force exerted by the (A) Fluid on the solid in a direction opposite to flow (B) Fluid on the solid in the direction of flow (C) Solid on the fluid (D) None of these
Last Answer : (B) Fluid on the solid in the direction of flow
Description : Forces acting on a particle settling in fluid are __________ forces. (A) Gravitational & buoyant (B) Centrifugal & drag (C) Gravitational or centrifugal buoyant drag (D) External, drag & viscous
Last Answer : (C) Gravitational or centrifugal buoyant drag
Description : The specific surface of spherical particles is given by (where D and ρ are diameter and density of particle). (A) 6/D.ρ (B) 2/D.ρ (C) 4/D.ρ (D) 12/D.ρ
Last Answer : (A) 6/D.ρ
Description : The specific surface of spherical particles is proportional to (where, Dp = diameter of particle). (A) D2 p (B) Dp (C) 1/Dp (D) 1/D2p
Last Answer : (C) 1/Dp
Description : Pascal's law is valid, only when the fluid is (A) Frictionless and at rest (B) At rest (C) At rest and when the frictionless fluid is in motion (D) None of these
Last Answer : (B) At rest
Description : The continuity equation (A) Relates mass flow rate along a stream tube (B) Relates work and energy (C) Stipulates that Newton's second law of motion must be satisfied at every point in the fluid (D) None of these
Last Answer : (A) Relates mass flow rate along a stream tube
Description : A Newtonian fluid is that (A) Which follows Newton's law of motion (B) Which needs a minimum shear, before it starts deforming (C) For which shear & deformation are related as T = µ (∂u/∂y) (D) None of these
Last Answer : (C) For which shear & deformation are related as T = µ (∂u/∂y)
Description : Which of the following must be followed by the flow of a fluid (real or ideal)? (I) Newton's law of viscosity. (II) Newton's second law of motion. (III) The continuity equation. (IV) Velocity of boundary layer must be zero relative to ... . (A) I, II, III (B) II, III, V (C) I, II, V (D) II, IV, V
Last Answer : (B) II, III, V