The length of the tube necessary for the boundary layer to reach thecentre of the tube and for fully developed flow to be established is called the__________ length.(A) Equivalent(B) Transition(C) Prandtl mixing(D) None of these

The length of the tube necessary for the boundary layer to reach thecentre of the tube and for fully developed flow to be established is called the
__________ length.
(A) Equivalent
(B) Transition
(C) Prandtl mixing
(D) None of these
by

1 Answer

Answer :

(B) Transition
by

Related questions

For flow over a flat plate, the ratio of thermal boundary layer thickness, 'xt' and hydrodynamic boundary layer thickness 'x' is equal to (where, NPr = Prandtl number) (A) NPr (B) NPr 1/3 (C) NPr -1 (D) NPr -1/3

Description : For flow over a flat plate, the ratio of thermal boundary layer thickness, 'xt' and hydrodynamic boundary layer thickness 'x' is equal to (where, NPr = Prandtl number) (A) NPr (B) NPr 1/3 (C) NPr -1 (D) NPr -1/3

Last Answer : (B) NPr 1/3

The Prandtl mixing length is (A) Zero at the pipe wall and is a universal constant (B) Independent of radial distance from the pipe axis (C) Independent of the shear stress (D) Useful for computing laminar flow problems

Description : The Prandtl mixing length is (A) Zero at the pipe wall and is a universal constant (B) Independent of radial distance from the pipe axis (C) Independent of the shear stress (D) Useful for computing laminar flow problems

Last Answer : (D) Useful for computing laminar flow problems

Prandtl mixing length is (A) Applicable to laminar flow problems (B) A universal constant (C) Zero at the pipe wall (D) None of these

Description : Prandtl mixing length is (A) Applicable to laminar flow problems (B) A universal constant (C) Zero at the pipe wall (D) None of these

Last Answer : (C) Zero at the pipe wall

Thickness of thermal boundary layer is more compared to that of hydrodynamic boundary layer, when the value of Prandtl number is (A) 1 (B) < 1 (C) > 1 (D) > 5

Description : Thickness of thermal boundary layer is more compared to that of hydrodynamic boundary layer, when the value of Prandtl number is (A) 1 (B) < 1 (C) > 1 (D) > 5

Last Answer : (B) < 1

. If Prandtl number is greater than the Schmidt number, then the (A) Thermal boundary layer lies inside the concentration boundary layer (B) Concentration boundary layer lies inside the thermal boundary layer (C) Thermal & concentration boundary layers are of equal thickness (D) Hydrodynamic (i.e., momentum) boundary layer is thicker than the other two

Description : . If Prandtl number is greater than the Schmidt number, then the (A) Thermal boundary layer lies inside the concentration boundary layer (B) Concentration boundary layer lies inside the thermal boundary ... (D) Hydrodynamic (i.e., momentum) boundary layer is thicker than the other two

Last Answer : (A) Thermal boundary layer lies inside the concentration boundary layer

Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Description : Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer. (A) Grashoff (B) Reynolds (C) Both 'a' & 'b' (D) Prandtl & Grashoff

Last Answer : (D) Prandtl & Grashoff

In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will (A) Decrease gradually (B) Increase gradually (C) Increase rapidly (D) Remain constant

Description : In a boundary layer developed along the flow, the pressure decreases in the downstream direction. The boundary layer thickness in this case will (A) Decrease gradually (B) Increase gradually (C) Increase rapidly (D) Remain constant

Last Answer : (B) Increase gradually

The Prandtl Pitot tube measures the (A) Velocity at a point in the flow (B) Pressure at a point (C) Average flow velocity (D) Pressure difference in pipe flow

Description : The Prandtl Pitot tube measures the (A) Velocity at a point in the flow (B) Pressure at a point (C) Average flow velocity (D) Pressure difference in pipe flow

Last Answer : (A) Velocity at a point in the flow

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

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

Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Description : Transition from laminar to turbulent zone in free convection heat transfer is governed by the critical value of (A) Grashoff number (B) Grashoff number & Reynolds number (C) Reynolds number (D) Grashoff number & Prandtl number

Last Answer : Option D

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

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

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

Description : 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

Last Answer : (A) Prandtl number is one

Which of the following is true about White and Black Box Testing Technique:- a) Equivalance partitioning, Decision Table and Control flow are White box Testing Techniques. b) Equivalence partitioning , Boundary Value Analysis , Data Flow are Black Box Testing Techniques. c) Equivalence partitioning , State Transition , Use Case Testing are black box Testing Techniques. d) Equivalence Partioning , State Transition , Use Case Testing and Decision Table are White Box Testing Techniques.

Description : Which of the following is true about White and Black Box Testing Technique:- a) Equivalance partitioning, Decision Table and Control flow are White box Testing Techniques. b) Equivalence partitioning ... , State Transition , Use Case Testing and Decision Table are White Box Testing Techniques.

Last Answer : c) Equivalence partitioning , State Transition , Use Case Testing are black box Testing Techniques.

Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger (D) Hot gases at moderate pressure are usually in the shell side of shell and tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger

The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is (A) Nusselt number (B) Sherwood number (C) Schmidt number (D) Stanton numbe

Description : The dimensionless group in mass transfer that is equivalent to Prandtl number in heat transfer is (A) Nusselt number (B) Sherwood number (C) Schmidt number (D) Stanton numbe

Last Answer : (C) Schmidt number

Pick out the wrong statement about a streamline. (A) It is always parallel to the main direction of the fluid flow (B) It is a line across which there is no flow and it is equivalent to a rigid boundary(C) Streamlines intersect at isolated point of zero velocity and infinitevelocity(D) The fluid lying between any two streamlines can be considered to be inisolation and the streamline spacing varies inversely as the velocity

Description : Pick out the wrong statement about a streamline. (A) It is always parallel to the main direction of the fluid flow (B) It is a line across which there is no flow and it is ... any two streamlines can be considered to be in isolation and the streamline spacing varies inversely as the velocity

Last Answer : (A) It is always parallel to the main direction of the fluid flow

The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is (A) 1.66(B) 88.66 (C) 3.66 (D) Dependent on NRe only

Description : The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is (A) 1.66 (B) 88.66 (C) 3.66 (D) Dependent on NRe only

Last Answer : (C) 3.66

The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is(A) 2.36(B) 4.36(C) 120.36(D) Dependent on NRe only

Description : The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe, where the wall heat flux is constant, is (A) 2.36 (B) 4.36 (C) 120.36 (D) Dependent on NRe only

Last Answer : (B) 4.36

Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Description : Bernoulli's equation describes the (A) Mechanical energy balance in potential flow (B) Kinetic energy balance in laminar flow (C) Mechanical energy balance in turbulent flow (D) Mechanical energy balance in boundary layer

Last Answer : (A) Mechanical energy balance in potential flow

For flow past a flat plate, if ‘x’ is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to (A) √x (B) 1/√x (C) x (D) 1/x Answe

Description : For flow past a flat plate, if ‘x’ is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to (A) √x (B) 1/√x (C) x (D) 1/x Answe

Last Answer : (A) √x

Boundary layer separation is characterised by one of the conditions given below, where 'Re' is the Reynolds number for the flow. Select the appropriate conditions. (A) Re << 1, accelerating flow (B) Re >> 1, accelerating flow (C) Re << 1, decelerating flow (D) Re >>1, decelerating flow

Description : Boundary layer separation is characterised by one of the conditions given below, where 'Re' is the Reynolds number for the flow. Select the appropriate conditions. (A) Re > 1, accelerating flow (C) Re >1, decelerating flow

Last Answer : (D) Re >>1, decelerating flow

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 these

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

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 (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads (D) Fanning friction factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number

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

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) varies linearly as the radial distance (C) An ideal fluid is the one, which has negligible surface tension and obeys the Newton's law of viscosity (D) Existence of the boundary layer in fluid flow is because of viscosity of the fluid

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

Boundary layer exists in flow (A) Of real fluids (B) Over flat surfaces only (C) In pipes only (D) Of ideal fluids only

Description : Boundary layer exists in flow (A) Of real fluids (B) Over flat surfaces only (C) In pipes only (D) Of ideal fluids only

Last Answer : (A) Of real fluids

The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids (A) Having high viscosities (B) Moving at low velocities (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The effect of solid boundary on the fluid flow is confined to the boundary layer, except for fluids (A) Having high viscosities (B) Moving at low velocities (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

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 boundary. (V) Fluid cannot penetrate a boundary. (A) I, II, III (B) II, III, V (C) I, II, V (D) II, IV, V

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

__________ flow means the flow of incompressible fluid with no shear. (A) Potential (B) Streamline (C) Creep (D) Boundary layer

Description : __________ flow means the flow of incompressible fluid with no shear. (A) Potential (B) Streamline (C) Creep (D) Boundary layer

Last Answer : (A) Potential

Existence of boundary layer in fluid flow is because of the (A) Surface tension (B) Fluid density (C) Fluid viscosity (D) Gravity forces

Description : Existence of boundary layer in fluid flow is because of the (A) Surface tension (B) Fluid density (C) Fluid viscosity (D) Gravity forces

Last Answer : (C) Fluid viscosity

The boundary layer is that part of a moving fluid, in which the fluid velocity is (A) Affected by the fluid flow pressure (B) Constant(C) Affected by the presence of a solid boundary(D) All (A), (B) and (C)

Description : The boundary layer is that part of a moving fluid, in which the fluid velocity is (A) Affected by the fluid flow pressure (B) Constant (C) Affected by the presence of a solid boundary (D) All (A), (B) and (C)

Last Answer : (C) Affected by the presence of a solid boundary

The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is (A) Pipe vibrations (B) Cavitation (C) Boundary layer separation (D) Fluctuation in liquid flow

Description : The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is (A) Pipe vibrations (B) Cavitation (C) Boundary layer separation (D) Fluctuation in liquid flow

Last Answer : (B) Cavitation

The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) (A) x1.5 (B) x0.8 (C) x-1.5 (D) x-0.8

Description : The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge) (A) x1.5 (B) x0.8 (C) x-1.5 (D) x-0.8

Last Answer : (B) x0.8

At the point of boundary layer separation in fluid flow, the (A) Shear stress is maximum (B) Velocity gradient is flat (C) Density variation is maximum (D) Shear stress is zero

Description : At the point of boundary layer separation in fluid flow, the (A) Shear stress is maximum (B) Velocity gradient is flat (C) Density variation is maximum (D) Shear stress is zero

Last Answer : Option A

When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is: (A) Free convection (B) Entry length problem in laminar forced conduction (developing thermal boundary layer) (C) Mixed convection (both free and forced) (D) Forced convection

Description : When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is: (A) Free convection (B) Entry length problem in laminar forced ... (developing thermal boundary layer) (C) Mixed convection (both free and forced) (D) Forced convection

Last Answer : (C) Mixed convection (both free and forced)

. The most widely used crude topping column in refineries is the__________ column.(A) Bubble-cap(B) Packed bed(C) Fluidised bed(D) Perforated plate

Description : . The most widely used crude topping column in refineries is the__________ column. (A) Bubble-cap (B) Packed bed (C) Fluidised bed (D) Perforated plate

Last Answer : (A) Bubble-cap

The optimum percentage of excess air for combustion depends upon the__________ of the fuel.(A) Type (solid, liquid or gaseous)(B) Calorific value(C) Sulphur content(D) Ignition temperature

Description : The optimum percentage of excess air for combustion depends upon the__________ of the fuel. (A) Type (solid, liquid or gaseous) (B) Calorific value (C) Sulphur content (D) Ignition temperature

Last Answer : (A) Type (solid, liquid or gaseous)

If the rate of gain of radial acceleration is 0.3 m per sec3 and full centrifugal ratio is developed. On the curve the ratio of the length of the transition curve of same radius on road and railway, is (A) 2.828 (B) 3.828 (C) 1.828 (D) 0.828

Description : If the rate of gain of radial acceleration is 0.3 m per sec3 and full centrifugal ratio is developed. On the curve the ratio of the length of the transition curve of same radius on road and railway, is (A) 2.828 (B) 3.828 (C) 1.828 (D) 0.828

Last Answer : (A) 2.828

Transition length for turbulent flow in smooth pipe is equal to __________ times the pipe diameter. (A) 0.5 (B) 5 (C) 50 (D) 500

Description : Transition length for turbulent flow in smooth pipe is equal to __________ times the pipe diameter. (A) 0.5 (B) 5 (C) 50 (D) 500

Last Answer : (C) 50

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

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

02. The separation of flow occurs when the hydrodynamic boundary layer thickness is reduced to zero. A) AgreeB) Disagree

Description : 02. The separation of flow occurs when the hydrodynamic boundary layer thickness is reduced to zero. A) Agree B) Disagree

Last Answer : A

An ideal flow of any fluid must satisfy (A) Pascal law (B) Newton's law of viscosity (C) Boundary layer theory (D) Continuity equation

Description : An ideal flow of any fluid must satisfy (A) Pascal law (B) Newton's law of viscosity (C) Boundary layer theory (D) Continuity equation

Last Answer : Answer: Option D

Pick out the wrong statement. (A) In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturated vapour feed (B) In small columns, local efficiency is larger than Murphree efficiency; in large columns local efficiency is smaller than Murphree efficiency (C) For Laminar flow over a plate of length L, the local mass transfer co￾efficient at a distance L from the leading edge is 1.5 × 10 -2m/s. Then the average mass transfer co-efficient for the plate is 2 × 10 -2m/s (D) The concentration and hydrodynamic boundary layers over a flat plate are of equal thickness, if Schmidt number is equal to unity

Description : Pick out the wrong statement. (A) In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturated vapour feed (B) In ... layers over a flat plate are of equal thickness, if Schmidt number is equal to unity

Last Answer : (C) For Laminar flow over a plate of length L, the local mass transfer co￾efficient at a distance L from the leading edge is 1.5 × 10 -2m/s. Then the average mass transfer co-efficient for the plate is 2 × 10 -2m/s

The secondary lymphoid tissues include the__________ and_____________ a. Thymus; Bone Marrow b. Bone Marrow; Tonsils c. Spleen; Thymus d. Spleen; Lymph Nodes

Description : The secondary lymphoid tissues include the__________ and_____________ a. Thymus; Bone Marrow b. Bone Marrow; Tonsils c. Spleen; Thymus d. Spleen; Lymph Nodes

Last Answer : d. Spleen; Lymph Nodes

Blades of disc harrow are sharpened from the_______ side penetrate more readily than blades sharpened from the__________ side a) convex, concave c) concave, convex b) Front, rear d) Rear, front

Description : Blades of disc harrow are sharpened from the_______ side penetrate more readily than blades sharpened from the__________ side a) convex, concave c) concave, convex b) Front, rear d) Rear, front

Last Answer : c) concave, convex

TIIC is sponsored by the__________. A. Government of Karnataka. B. Government of Andhra Pradesh. C. Government of Kerala. D. Government of Tamil Nadu.

Description : TIIC is sponsored by the__________. A. Government of Karnataka. B. Government of Andhra Pradesh. C. Government of Kerala. D. Government of Tamil Nadu.

Last Answer : D. Government of Tamil Nadu.

The value of the capacitor in a capacitor start motor controls the__________.

Last Answer : The value of the capacitor in a capacitor start motor controls the starting torque

Which of the following techniques is NOT a black box technique? a) State transition testing b) LCSAJ (Linear Code Sequence and Jump) c) syntax testing d) boundary value analysis

Description : Which of the following techniques is NOT a black box technique? a) State transition testing b) LCSAJ (Linear Code Sequence and Jump) c) syntax testing d) boundary value analysis

Last Answer : b) LCSAJ (Linear Code Sequence and Jump)

While mixing sand, gravel, and cement for the foundation of a house, a worker noticed a small bird hopping along the top of the foundation wall. The bird misjudged a hop and fell down one of the holes between the blocks. The bird was down too far for anyone to reach it and the hole was too small for it to fly out of. Someone suggested using two sticks to reach down into the hole and pull the bird out, but this idea was rejected for fear it would injure the fragile bird. What would be the easiest way to get the bird out of the hole without injuring it? -Riddles

Description : While mixing sand, gravel, and cement for the foundation of a house, a worker noticed a small bird hopping along the top of the foundation wall. The bird misjudged a hop and fell down one of the holes ... . What would be the easiest way to get the bird out of the hole without injuring it? -Riddles

Last Answer : Since they had plenty of sand available, they could pour a little at a time into the hole. The bird would constantly keep shifting its position so that it stood on the rising sand.

Consider the following statements: Mitra’s hyperbolic transition design is based on the principle that : 1. Flow depth in the canal, as well as the discharge, is constant 2. width of the canal varies along with the discharge 3. Rate of change of velocity per unit length of transition is constant throughout the length of the transition. Which of these statements are correct ? a) 1, 2 and 3 b) 1 and 2 only c) 2 and 3 only d) 1 and 3 only

Description : Consider the following statements: Mitra's hyperbolic transition design is based on the principle that : 1. Flow depth in the canal, as well as the discharge, is constant 2. width of the canal varies along with the discharge 3. Rate ... a) 1, 2 and 3 b) 1 and 2 only c) 2 and 3 only d) 1 and 3 only

Last Answer : d) 1 and 3 only