Mach number is defined as the ratio of the local flow velocity to the sonic velocity in the fluid. For what value of Mach number, the gases are considered incompressible? (A) < 0.3 (B) > 3 (C) 50 (D) 1

Mach number is defined as the ratio of the local flow velocity to the
sonic velocity in the fluid. For what value of Mach number, the gases are
considered incompressible?
(A) < 0.3
(B) > 3
(C) 50
(D) 1
by

1 Answer

Answer :

(A) < 0.3
by

Related questions

Upto what value of 'Mach number', a fluid may be considered as incompressible? (A) 0.03 (B) 0.3 (C) 3(D) 10

Description : Upto what value of 'Mach number', a fluid may be considered as incompressible? (A) 0.03 (B) 0.3 (C) 3 (D) 10

Last Answer : (D) 10

Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the total volume to the volume of voids in the bed (C) Mach number in an incompressible fluid is always unity (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Description : Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

A flow is called super-sonic if the (A) Velocity of flow is very high (B) Discharge is difficult to measure (C) Mach number is between 1 and 6 (D) None of these

Description : A flow is called super-sonic if the (A) Velocity of flow is very high (B) Discharge is difficult to measure (C) Mach number is between 1 and 6 (D) None of these

Last Answer : Answer: Option C

For ideally incompressible fluid, the Mach number will be(A) 1.5 (B) 1 (C) 0 (D) 5

Description : For ideally incompressible fluid, the Mach number will be (A) 1.5 (B) 1 (C) 0 (D) 5

Last Answer : (B) 1

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)

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

When the Mach number is less than unity, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

Description : When the Mach number is less than unity, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

Last Answer : Answer: Option A

When the Mach number is more than 6, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

Description : When the Mach number is more than 6, the flow is called (A) Sub-sonic flow (B) Sonic flow (C) Super-sonic flow (D) Hyper-sonic flow

Last Answer : Answer: Option D

A flow is called sub-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) More than 6

Description : A flow is called sub-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) More than 6

Last Answer : Answer: Option A

A flow is called hyper-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) None of these

Description : A flow is called hyper-sonic, if the Mach number is (A) Less than unity (B) Unity (C) Between 1 and 6 (D) None of these

Last Answer : Answer: Option D

When the Mach number is between __________ the flow is called super-sonic flow. (A) 1 and 2.5 (B) 2.5 and 4 (C) 4 and 6 (D) 1 and 6

Description : When the Mach number is between __________ the flow is called super-sonic flow. (A) 1 and 2.5 (B) 2.5 and 4 (C) 4 and 6 (D) 1 and 6

Last Answer : Answer: Option D

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. (du/dy) n the value of 'n' for pseudoplastic and Dilatant fluid are < 1 and >1 respectively (C) Shear stress for Newtonian fluid is proportional to the rate of shear in the direction perpendicular to motion (D) With increase in the Mach number >0.6, the drag co-efficient decreases in case of compressible fluids

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

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

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

08. The ratio of velocity of fluid in an undisturbed stream to the velocity of sound wave is known as Mach number. A) Yes B) No

Description : 08. The ratio of velocity of fluid in an undisturbed stream to the velocity of sound wave is known as Mach number. A) Yes B) No

Last Answer : A

The Euler's equation for the motion of liquids is based upon the assumption that (A) The fluid is non - viscous, homogeneous and incompressible (B) The velocity of flow is uniform over the section (C) The flow is continuous, steady and along the stream line (D) All of the above

Description : The Euler's equation for the motion of liquids is based upon the assumption that (A) The fluid is non - viscous, homogeneous and incompressible (B) The velocity of flow is uniform over the section (C) The flow is continuous, steady and along the stream line (D) All of the above

Last Answer : Answer: Option D

04. All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow. A) Correct B) Incorrect

Description : 04. All the gases are considered to have compressible flow and all the liquids are considered to have incompressible flow. A) Correct B) Incorrect

Last Answer : A

In case of supersonic flow of a fluid through pipeline, the 'Mach number' is (A) 0 (B) 1 (C) < 1 (D) > 1

Description : In case of supersonic flow of a fluid through pipeline, the 'Mach number' is (A) 0 (B) 1 (C) < 1 (D) > 1

Last Answer : (D) > 1

For one dimensional flow of an incompressible fluid in unsteady state in x-direction, the continuity equation is given by (A) ∂u/∂x = 0 (B) ∂(ρu)/∂x = 0 (C) (∂u/∂x) = - (∂ρ/∂t) (D) ∂ρ/∂t = 0

Description : For one dimensional flow of an incompressible fluid in unsteady state in x-direction, the continuity equation is given by (A) ∂u/∂x = 0 (B) ∂(ρu)/∂x = 0 (C) (∂u/∂x) = - (∂ρ/∂t) (D) ∂ρ/∂t = 0

Last Answer : (A) ∂u/∂x = 0

A fluid element has a velocity V = -y 2 . xi + 2yx 2 . j. The motion at (x, y) = (1/√2, 1) is (A) Rotational and incompressible (B) Rotational and compressible (C) Irrotational and compressible (D) Irrotational and incompressible

Description : A fluid element has a velocity V = -y 2 . xi + 2yx 2 . j. The motion at (x, y) = (1/√2, 1) is (A) Rotational and incompressible (B) Rotational and compressible (C) Irrotational and compressible (D) Irrotational and incompressible

Last Answer : (B) Rotational and compressible

Which of the following denotes the effect of compressibility in fluid flow? (A) Weber number (B) Mach number (C) Euler number (D) Reynolds number

Description : Which of the following denotes the effect of compressibility in fluid flow? (A) Weber number (B) Mach number (C) Euler number (D) Reynolds number

Last Answer : (B) Mach numbe

The Mach number for hypersonic flow of compressible fluid is (A) 1 (B) > 1 (C) > 4 (D) < 2

Description : The Mach number for hypersonic flow of compressible fluid is (A) 1 (B) > 1 (C) > 4 (D) < 2

Last Answer : (C) > 4

Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate. (A) Elastic (B) Viscous (C) Gravity (D) None of these

Description : Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate. (A) Elastic (B) Viscous (C) Gravity (D) None of these

Last Answer : (A) Elastic

Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate. (A) Elastic (B) Viscous (C) Gravity (D) None of these

Description : Mach number is important in a fluid flow problem, when the inertia and __________ forces predominate. (A) Elastic (B) Viscous (C) Gravity (D) None of these

Last Answer : A) Elastic

__________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical. (A) Mach (B) Reynolds (C) Froude (D) Weber

Description : __________ number determines whether the fluid flow in an open channel is supercritical, critical or sub-critical. (A) Mach (B) Reynolds (C) Froude (D) Weber

Last Answer : (C) Froude

Mach number is the ratio of the speed of the (A) Fluid to that of the light (B) Light to that of the fluid (C) Fluid to that of the sound (D) Sound to that of the fluid

Description : Mach number is the ratio of the speed of the (A) Fluid to that of the light (B) Light to that of the fluid (C) Fluid to that of the sound (D) Sound to that of the fluid

Last Answer : (C) Fluid to that of the sound

Bernoulli's equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli's equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is steady. C. Fluid flow is uniform & turbulent. D. Fluid is compressible. E. Fluid is incompressible. (A) A, C, D (B) B, D, E (C) A, B, E (D) A, D, E

Description : Bernoulli's equation for fluid flow is derived following certain assumptions. Out of the assumptions listed below, which set of assumptions is used in derivation of Bernoulli's equation? A. Fluid flow is frictionless & irrotational. B. Fluid flow is ... A, C, D (B) B, D, E (C) A, B, E (D) A, D, E

Last Answer : (C) A, B, E

Which of the following assumptions enables the Euler's equation of motion to be integrated? (A) The fluid is incompressible (B) The fluid is non-viscous (C) The continuity equation is satisfied (D) The flow is rotational and incompressible

Description : Which of the following assumptions enables the Euler's equation of motion to be integrated? (A) The fluid is incompressible (B) The fluid is non-viscous (C) The continuity equation is satisfied (D) The flow is rotational and incompressible

Last Answer : (A) The fluid is incompressible

Select the wrong statement pertaining to flow of an incompressible fluid through a Venturimeter. (A) For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal to that leaving the Venturimeter(B) Discharge of fluid through a Venturimeter depends upon the gagedifference irrespective of the orientation of Venturimeter(C) Venturimeter occupies less space than an orificemeter(D) Venturimeter incurs less power loss compared to an equivalentorificemeter

Description : Select the wrong statement pertaining to flow of an incompressible fluid through a Venturimeter. (A) For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal ... than an orificemeter (D) Venturimeter incurs less power loss compared to an equivalent orificemeter

Last Answer : (C) Venturimeter occupies less space than an orificemeter

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) d2(C) d2.5(D) d

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

Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter 'd'? (A) At the centre (B) At d/4 from the wall (C) At the wall (D) At d/8 from the wall

Description : Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter 'd'? (A) At the centre (B) At d/4 from the wall (C) At the wall (D) At d/8 from the wall

Last Answer : (C) At the wall

In an incompressible flow of fluid, the fluid (A) Temperature remains constant (B) Compressibility is greater than zero (C) Density does not change with pressure & temperature (D) Is frictionless

Description : In an incompressible flow of fluid, the fluid (A) Temperature remains constant (B) Compressibility is greater than zero (C) Density does not change with pressure & temperature (D) Is frictionless

Last Answer : (C) Density does not change with pressure & temperature

__________ 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

What is the ratio of total kinetic energy of fluid passing per second to the value obtained on the basis of average velocity (for laminar flow through a circular pipe)? (A) 0.5 (B) 1 (C) 1.5 (D) 2

Description : What is the ratio of total kinetic energy of fluid passing per second to the value obtained on the basis of average velocity (for laminar flow through a circular pipe)? (A) 0.5 (B) 1 (C) 1.5 (D) 2

Last Answer : (D) 2

In fluid flow, the stagnation point is defined as a point, where the __________ is zero. (A) Flow velocity (B) Pressure (C) Total energy (D) All (A), (B) and (C)

Description : In fluid flow, the stagnation point is defined as a point, where the __________ is zero. (A) Flow velocity (B) Pressure (C) Total energy (D) All (A), (B) and (C)

Last Answer : (A) Flow velocity

A flow in which the volume of a fluid and its density does not change during the flow is called _________ flow. (A) Incompressible (B) Compressible (C) Viscous (D) None of these

Description : A flow in which the volume of a fluid and its density does not change during the flow is called _________ flow. (A) Incompressible (B) Compressible (C) Viscous (D) None of these

Last Answer : Answer: Option A

Surging basically implies A. Unsteady, periodic and reversed flow B. Forward motion of air at a speed above sonic velocity C. The surging action due to the blast of air produced in a compressor D. Forward movement of aircraft

Description : Surging basically implies A. Unsteady, periodic and reversed flow B. Forward motion of air at a speed above sonic velocity C. The surging action due to the blast of air produced in a compressor D. Forward movement of aircraft

Last Answer : ANSWER : A

The velocity at which the flow changes from laminar flow to turbulent flow is called (A) Critical velocity (B) Velocity of approach (C) Sub-sonic velocity (D) Super-sonic velocity

Description : The velocity at which the flow changes from laminar flow to turbulent flow is called (A) Critical velocity (B) Velocity of approach (C) Sub-sonic velocity (D) Super-sonic velocity

Last Answer : Answer: Option A

The value of bulk modulus of a fluid is required to determine (A) Reynold's number (B) Froude's number (C) Mach number (D) Euler's number

Description : The value of bulk modulus of a fluid is required to determine (A) Reynold's number (B) Froude's number (C) Mach number (D) Euler's number

Last Answer : Answer: Option C

The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonian fluid in a circular pipe is (A) 0.5 (B) 1 (C) 2 (D) 0.66

Description : The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonian fluid in a circular pipe is (A) 0.5 (B) 1 (C) 2 (D) 0.66

Last Answer : (A) 0.5

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 fluid velocity in a circular pipe flow is maximum at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows

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

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

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

For an incompressible fluid, the bulk modulus of elasticity is (A) 5 kg/m3 (B) ∞ N/m2 (C) 1 N (D) 0 N/m

Description : For an incompressible fluid, the bulk modulus of elasticity is (A) 5 kg/m3 (B) ∞ N/m2 (C) 1 N (D) 0 N/m

Last Answer : (B) ∞ N/m2

Pick out the correct statement pertaining to the flow through a converging-diverging tube. (A) The value of Mach number is always unity at the throat (B) No shock wave develops in the tube when the Mach number at exit is greater than unity (C) Throughout the converging portion of the tube, the density increases in the downstream direction (D) None of these

Description : Pick out the correct statement pertaining to the flow through a converging-diverging tube. (A) The value of Mach number is always unity at the throat (B) No shock wave develops in the tube ... the converging portion of the tube, the density increases in the downstream direction (D) None of these

Last Answer : (B) No shock wave develops in the tube when the Mach number at exit is greater than unity

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

. A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an __________ fluid. (A) Newtonian (B) Non-Newtonian (C) Ideal (D) Incompressible

Description : . A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an __________ fluid. (A) Newtonian (B) Non-Newtonian (C) Ideal (D) Incompressible

Last Answer : (A) Newtonian

A fluid is the one, which (A) Cannot remain at rest under the action of shear force (B) Continuously expands till it fills any container (C) Is incompressible (D) Permanently resists distortion

Description : A fluid is the one, which (A) Cannot remain at rest under the action of shear force (B) Continuously expands till it fills any container (C) Is incompressible (D) Permanently resists distortion

Last Answer : (A) Cannot remain at rest under the action of shear force

In an incompressible fluid, the density is (A) Greatly affected by moderate changes in pressure (B) Greatly affected only by moderate changes in temperature (C) Not affected with moderate change in temperature & pressure (D) Sensible to changes in both temperature & pressure

Description : In an incompressible fluid, the density is (A) Greatly affected by moderate changes in pressure (B) Greatly affected only by moderate changes in temperature (C) Not affected with moderate change in temperature & pressure (D) Sensible to changes in both temperature & pressure

Last Answer : (C) Not affected with moderate change in temperature & pressure

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

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

An ideal fluid is (A) Non-viscous (B) Incompressible (C) Both (A) & (B) (D) Neither (A) & (B

Description : An ideal fluid is (A) Non-viscous (B) Incompressible (C) Both (A) & (B) (D) Neither (A) & (B

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

A fluid is a substance, that (A) Has to be kept in a closed container (B) Is almost incompressible (C) Has zero shear stress (D) Flows when even a small shear is applied to it

Description : A fluid is a substance, that (A) Has to be kept in a closed container (B) Is almost incompressible (C) Has zero shear stress (D) Flows when even a small shear is applied to it

Last Answer : (D) Flows when even a small shear is applied to it