At Pr > 1, conduction in an ordinary fluid flowing through a heated
pipe is limited to the
(A) Buffer zone
(B) Turbulent core
(C) Both (A) and (B)
(D) Viscous sub-layer
Description : Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is (A) 0.2 (B) 0.4 (C) 0.6 (D) 0.8
Last Answer : (C) 0.6
Description : At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated pipe? (A) 0.5 (B) < 0.5 (C) > 0.6 (D) < 0.1
Last Answer : (C) > 0.6
Description : Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is (A) 0.1 (B) > 1 (C) < 1 (D) 1
Last Answer : (A) 0.1
Description : Heat transfer in the laminar sub-layer in case of a liquid flowing through a pipe, is mostly by (A) Eddies current (B) Conduction (C) Convection (D) None of these
Last Answer : (B) Conduction
Description : The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz
Last Answer : (D) Nu, Gz
Description : essure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as (A) V1.8 (B) V-0.2 (C) V2.7 (D) V
Last Answer : (D) V
Description : Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone. (A) Laminar (B) Transition (C) Both 'a' & 'b' (D) Highly turbulent
Last Answer : (D) Highly turbulent
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 fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer coefficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8
Last Answer : (B) d -0.2
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 : When the pipe Reynold's number is 6000, the flow is generally (A) Viscous (B) Laminar (C) Turbulent (D) Transition
Last Answer : (C) Turbulent
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 : Which of the following fluid forces are not considered in the NavierStoke's equation? (A) Gravity forces (B) Viscous forces (C) Pressure forces (D) Turbulent forces
Last Answer : (D) Turbulent forces
Description : Which of the fluid forces are not considered in the Reynold's equation of flow? (A) Viscous forces (B) Turbulent forces (C) Pressure forces (D) Compressibility forces
Last Answer : (D) Compressibility forces
Description : Turbulent flow generally occurs for cases involving (A) Highly viscous fluid (B) Very narrow passages (C) Very slow motion (D) None of these
Last Answer : (D) None of these
Description : Pick out the wrong statement. (A) A fluid mass is free from shearing forces, when it is made to rotate with a uniform velocit (B) Newton's law of viscosity is not applicable to the ... types of bearings (D) Rise of water in capillary tubes reduces with the increasing diameter of capillary tubes
Last Answer : (B) Newton's law of viscosity is not applicable to the turbulent flow of fluid with linear velocity distribution
Description : _________ fluid force is not considered in the Navier-Stokes equation. (A) Turbulent (B) Viscous (C) Gravity (D) Pressure
Last Answer : (A) Turbulent
Description : For __________ Prandtl number values, the heat conduction will be negligible in the buffer zone. (A) Extremely low (B) Low (C) High (D) No
Last Answer : (C) High
Description : The head loss in turbulent flow in pipe is proportional to(where, V = velocity of fluid through the pipe) (A) V 2 (B) 1/V 2 (C) 1/V (D) V
Last Answer : (A) V
Description : For turbulent flow of an incompressible fluid through a pipe, the flow rate ‘Q’ is proportional to (Δ P)n, where ΔP is the pressure drop. The value of exponent 'n' is (A) 1 (B) 0 (C) < 1 (D) > 1
Last Answer : (C) < 1
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 : Transition from laminar flow to turbulent flow in fluid flow through a pipe does not depend upon the (A) Length of the pipe (B) Diameter of the pipe (C) Density of the fluid (D) Velocity of the fluid
Last Answer : (A) Length of the pipe
Description : he pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe ... then the pressure drop in this case will be (A) Δp (B) 2Δp (C) Δp 2 (D) Δp/2
Last Answer : (B) 2Δp
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 : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C
Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C
Description : In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow? (A) ... level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe
Last Answer : (B) Water flow in the suction and discharge pipe of a reciprocating pump
Description : In turbulent flow, a rough pipe has the same friction factor as a smooth pipe (A) In the zone of complete turbulence (B) When the roughness projections are much smaller than the thickness of ... ) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number
Last Answer : (B) When the roughness projections are much smaller than the thickness of the laminar film
Description : Applicability of Bernoulli's equation is limited to a/an __________ fluid, that does not exchange shaft work with the surroundings. (A) Incompressible (B) Non-viscous (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) and (B)
Description : In a fully turbulent flow (Re > 10 5 ) in a pipe of diameter 'd', for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is (A) d (B) d 2 (C) d 2.5 (D) d
Last Answer : (C) d 2.5
Description : In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity) (A) Vavg (B) 1.2 Vavg (C) 1.5 Vavg (D) 1.8 Vavg
Last Answer : (B) 1.2 Vavg
Description : Pick out the correct statement pertaining to transition/ entrance length in fluid flow. (A) The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change ... pipe of diameter 'd' is equal to 50 D (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : For turbulent flow of Newtonian fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is (A) 0.5 (B) 1 (C) 0.66 (D) < 0.5
Last Answer : (B) 1
Description : Transition length for a turbulent fluid entering into a pipe is around __________ times the pipe diameter. (A) 5 (B) 50 (C) 500 (D) 5000
Last Answer : (B) 50
Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number
Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads
Description : Pick out the wrong statement. (A) The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere (B) ... ) The earth's atmosphere is an envelope of gases extending upto a height of about 200 kms
Last Answer : (A) The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere
Description : At what value of Prandtl number, the hydrodynamic and thermal boundary layers of a fluid flowing over a heated plate will be identical? (A) 1 (B) < 1 (C) > 1 (D) None of these
Last Answer : (A) 1
Description : The normal stress is the same in all directions at a point in a fluid, when the fluid is (A) Non-viscous (B) Incompressible (C) Both (A) and (B) (D) Having no motion of one fluid layer relative to the other
Last Answer : (D) Having no motion of one fluid layer relative to the other
Description : The region of biosphere reserve which is legally protected and where no human activity is allowed is known as (a) buffer zone (b) transition zone (c) restoration zone (d) core zone.
Last Answer : (d) core zone.
Description : The region of Biosphere Reserve which is legally protected and where no human activity is allowed is known as: (1) Buffer zone (2) Transition zone (3) Restoration zone (4) Core zone
Last Answer : (4) Core zone
Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000
Last Answer : (D) > 10000
Description : 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 (A) Pipe length (B) Fluid velocity in the pipe (C) Time taken to close the valve (D) All (A), (B) and (C)
Description : Shear stress in a fluid flowing in a round pipe (A) Varies parabolically across the cross-section (B) Remains constant over the cross-section (C) Is zero at the centre and varies linearly with the radius (D) Is zero at the wall and increases linearly to the centre
Last Answer : (C) Is zero at the centre and varies linearly with the radius
Description : The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is (A) Parabolic (B) Flat (C) Flat near the wall and parabolic in the middle (D) Parabolic near the wall and flat in the middle
Last Answer : (D) Parabolic near the wall and flat in the middle
Description : Reynolds number of a fluid flowing in a circular pipe is 10,000. What will be the Reynolds number when the fluid velocity is decreased by 30% & the pipe diameter is increased by 30%? (A) 9,100 (B) 13,000 (C) 7,000 (D) 2,550
Last Answer : (A) 9,100
Description : Bulk of the convective heat transfer resistance from a hot tube surfaceto the fluid flowing in it, is (A) In the central core of the fluid (B) Uniformly distributed throughout the fluid (C) Mainly confined to a thin film of fluid near the surface (D) None of these
Last Answer : (C) Mainly confined to a thin film of fluid near the surface
Description : Which of the following ECG waveforms characterizes conduction of an electrical impulse through the left ventricle? a) QRS complex The QRS complex represents ventricular depolarization b) P ... QT interval is an ECG characteristic reflecting the time from ventricular depolarization to repolarization.
Last Answer : a) QRS complex The QRS complex represents ventricular depolarization
Description : The Bernoulli's equation is based on the assumption that (A) There is no loss of energy of the liquid flowing (B) The velocity of flow is uniform across any cross-section of the pipe (C) No force except gravity acts on the fluid (D) All of the above
Last Answer : Answer: Option D
Description : Transition from laminar flow to turbulent flow is aided by the (A) Surface roughness and curvature (i.e. sharp corners) (B) Vibration (C) Pressure gradient and the compressibility of the flowing medium (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : A flow in which __________ force is dominating over the viscosity is called turbulent flow. (A) Elastic (B) Surface tension (C) Viscous (D) Inertia
Description : Rain drops falling through atmospheric air attain limited terminal velocity, because of (A) Upward thrust due to air (B) Viscous force exerted by air (C) Surface tension effects of water (D) Force of gravity
Last Answer : Option B