The friction factor for turbulent flow in a hydraulically smooth pipe (A) Depends only on Reynolds number (B) Does not depend on Reynolds number (C) Depends on the roughness (D) None of these

The friction factor for turbulent flow in a hydraulically smooth pipe
(A) Depends only on Reynolds number
(B) Does not depend on Reynolds number
(C) Depends on the roughness
(D) None of these
by

1 Answer

Answer :

(A) Depends only on Reynolds number
by

Related questions

In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of (A) Relative roughness (B) Absolute roughness (C) Friction co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)

Description : In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said ... co-efficient for flows at equal Reynold number (D) All (A), (B) & (C)

Last Answer : (C) Friction co-efficient for flows at equal Reynold number

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 the laminar film (C) Everywhere in the transition zone (D) When the friction factor is independent of the Reynold's number

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

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

Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1 . If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe , will (A) Increase (B) Decrease (C) Remain unchanged (D) Increase or decrease depending on the pipe material

Description : Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1 . If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe , will (A) Increase (B) Decrease (C) Remain unchanged (D) Increase or decrease depending on the pipe material

Last Answer : (A) Increase

A pipe is defined as 'hydraulically smooth', if the friction factor (A) Is not a function of Reynolds number (B) For a given Reynolds number remains constant even on further smoothening of the pipe (C) Is zero irrespective of the Reynolds number (D) None of these

Description : A pipe is defined as 'hydraulically smooth', if the friction factor (A) Is not a function of Reynolds number (B) For a given Reynolds number remains constant even on further smoothening of the pipe (C) Is zero irrespective of the Reynolds number (D) None of these

Last Answer : (B) For a given Reynolds number remains constant even on further smoothening of the pipe

For a given Reynolds number, in a hydraulically smooth pipe, further smoothening __________ the friction factor. (A) Brings about no further reduction of (B) Increases (C) Decreases (D) None of these

Description : For a given Reynolds number, in a hydraulically smooth pipe, further smoothening __________ the friction factor. (A) Brings about no further reduction of (B) Increases (C) Decreases (D) None of these

Last Answer : (A) Brings about no further reduction of

Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Fanning friction factor for laminar flow of fluid in a circular pipe is (A) Not a function of the roughness of pipe wall (B) Inversely proportional to Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Isothermal turbulent flow of a fluid results in decrease of its pressure, which depends on the (A) Wall roughness (B) Reynolds number (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Friction factor for fluid flow in pipe does not depend upon the (A) Pipe length (B) Pipe roughness (C) Fluid density & viscosity (D) Mass flow rate of fluid

Description : Friction factor for fluid flow in pipe does not depend upon the (A) Pipe length (B) Pipe roughness (C) Fluid density & viscosity (D) Mass flow rate of fluid

Last Answer : A) Pipe length

The friction factor is (A) Always inversely proportional to the Reynolds number (B) Not dimensionless (C) Not dependent on the roughness of the pipe (D) None of these

Description : The friction factor is (A) Always inversely proportional to the Reynolds number (B) Not dimensionless (C) Not dependent on the roughness of the pipe (D) None of these

Last Answer : (D) None of these

In the complete turbulence zone (in rough pipes), the (A) Rough and smooth pipes have the same friction factor (B) Laminar film covers the roughness projections (C) Friction factor depends upon NRe only (D) Friction factor is independent of the relative roughness

Description : In the complete turbulence zone (in rough pipes), the (A) Rough and smooth pipes have the same friction factor (B) Laminar film covers the roughness projections (C) Friction factor depends upon NRe only (D) Friction factor is independent of the relative roughness

Last Answer : (D) Friction factor is independent of the relative roughness

. 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 increasing Reynolds number (C) Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius) (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

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

For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a __________ relationship. (A) Logarithmic (B) Linear (C) Hyperbolic (D) Parabolic

Description : For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance 'd' measured from the wall of the pipe and the friction velocity 'v', and it follows a __________ relationship. (A) Logarithmic (B) Linear (C) Hyperbolic (D) Parabolic

Last Answer : (A) Logarithmic

Which of the following quantities are computed by using the hydraulic radius for non-circular ducts? (A) Velocity and relative roughness (B) Head loss and velocity (C) Reynold number, relative roughness and head loss (D) Reynolds number and friction factor

Description : Which of the following quantities are computed by using the hydraulic radius for non-circular ducts? (A) Velocity and relative roughness (B) Head loss and velocity (C) Reynold number, relative roughness and head loss (D) Reynolds number and friction factor

Last Answer : (C) Reynold number, relative roughness and head loss

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) Discharge of water by a centrifugal pump being run at a constant rpm (B) Water flow in the suction and discharge pipe of a reciprocating pump (C) Water discharge from a vertical vessel in which constant level is maintained (D) Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe

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

The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8

Description : The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re 0.8 , where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient ... pipe diameter (D) as (A) D-1.8 (B) D-0.2 (C) D0.2 (D) D1.8

Last Answer : (B) D-0.2

When the pipe Reynold's number is 6000, the flow is generally (A) Viscous(B) Laminar(C) Turbulent(D) Transition

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

During ageing of fluid carrying pipes, the (A) Pipe becomes smoother with use (B) Friction factor increases linearly with time (C) Absolute roughness decreases with time (D) Absolute roughness increases linearly with time

Description : During ageing of fluid carrying pipes, the (A) Pipe becomes smoother with use (B) Friction factor increases linearly with time (C) Absolute roughness decreases with time (D) Absolute roughness increases linearly with time

Last Answer : (D) Absolute roughness increases linearly with time

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

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

Location of vena-contracta in an orificemeter does not depend upon the (A) Type of orifice (B) Density, viscosity & compressibility of the fluid (C) Ratio of pipe diameter to orifice diameter (D) Pipe roughness

Description : Location of vena-contracta in an orificemeter does not depend upon the (A) Type of orifice (B) Density, viscosity & compressibility of the fluid (C) Ratio of pipe diameter to orifice diameter (D) Pipe roughness

Last Answer : (A) Type of orifice

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)

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)

For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as (A) Re 0.33 (B) Re 0.53 (C) Re 0.83 (D) Re

Description : For turbulent mass transfer in pipes, the Sherwood number depends on the Reynolds number as (A) Re 0.33 (B) Re 0.53 (C) Re 0.83 (D) Re

Last Answer : (C) Re 0.83

All analogy equations connecting friction factor and heat transfer co￾efficient apply only to (A) Wall or skin friction (B) Form friction (C) Both (A) and (B) (D) Turbulent flow

Description : All analogy equations connecting friction factor and heat transfer co￾efficient apply only to (A) Wall or skin friction (B) Form friction (C) Both (A) and (B) (D) Turbulent flow

Last Answer : (A) Wall or skin friction

Pressure drag does not depend upon the(A) Roughness of surface of the body (B) Pressure of main flow only (C) Length of the body in flow direction (D) All (A), (B) and (C)

Description : Pressure drag does not depend upon the (A) Roughness of surface of the body (B) Pressure of main flow only (C) Length of the body in flow direction (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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(A) f1 = f2 (B) f1 < f2 (C) f1 > f2 (D) Data not sufficient to relate f1 & f2

Description : 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. (A) f1 = f2 (B) f1 < f2 (C) f1 > f2 (D) Data not sufficient to relate f1 & f2

Last Answer : (C) f1 > f2

What is the value of Fanning friction factor f ' for smooth pipe at NRe = 10 6 approximately? (A) 0.003 (B) 0.01 (C) 0.1(D) 0.3

Description : What is the value of Fanning friction factor f ' for smooth pipe at NRe = 10 6 approximately? (A) 0.003 (B) 0.01 (C) 0.1 (D) 0.3

Last Answer : (A) 0.003

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

The discharge co-efficient for an orifice meter does not depend upon the (A) Pipe length (B) Ratio of pipe diameter to orifice diameter (C) Type of orifice & the Reynolds number (D) Pipe diameter

Description : The discharge co-efficient for an orifice meter does not depend upon the (A) Pipe length (B) Ratio of pipe diameter to orifice diameter (C) Type of orifice & the Reynolds number (D) Pipe diameter

Last Answer : (A) Pipe length

Colebrook equation for friction factor in turbulent flow is given by, f -0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to (A) 0(B) 1 (C) ∞ (D) 0.5

Description : Colebrook equation for friction factor in turbulent flow is given by, f -0.5 = -4 loge [(ε/D) + (1.26/NRe √F). It reduces to Nikuradse equation for a value of (ϵ/D) equal to (A) 0 (B) 1 (C) ∞ (D) 0.5

Last Answer : (B) 1

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

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

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

Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Description : Nusselt number is related to the Reynolds number (Re) in turbulent & laminar flow respectively as (A) Re0.5, Re0.8 (B) Re0.8, Re-0.5 (C) Re0.8, Re0.5 (D) Re-0.8, Re0.5

Last Answer : (C) Re0.8, Re0.5

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

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

For pipes, turbulent flow occurs when Reynolds number is(A) Less than 2000 (B) Between 2000 and 4000 (C) More than 4000 (D) Less than 4000

Description : For pipes, turbulent flow occurs when Reynolds number is (A) Less than 2000 (B) Between 2000 and 4000 (C) More than 4000 (D) Less than 4000

Last Answer : Answer: Option C

Define. i) Streamline flow ii) Turbulent flow Give significance of Reynold’s number.

Description : Define. i) Streamline flow ii) Turbulent flow Give significance of Reynold’s number.

Last Answer : i) Streamline flow The flow of liquid in which every particle of liquid moves in the same direction of flow of liquid is called streamline flow. ii) Turbulent flow The flow of liquid in which every ... to 3000 liquid flow is unstable. (3)When R is greater than 3000 liquid flow is turbulent. 

Stone ware pipes are A. Highly resistant to sulphide corrosion B. Highly impervious C. Hydraulically efficient because of their smooth interior surface D. Especially suited to pressure pipes

Description : Stone ware pipes are A. Highly resistant to sulphide corrosion B. Highly impervious C. Hydraulically efficient because of their smooth interior surface D. Especially suited to pressure pipes

Last Answer : ANS: D

According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor)(A) 2f(B) f(C) f/2(D) f/4

Description : According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor) (A) 2f (B) f (C) f/2 (D) f/4

Last Answer : (C) f/2

Reynold's analogy states that (where, St = Stanton number f = friction factor) (A) St = f/2 (B) St = f/4 (C) St = 4f (D) St = f 1/2

Description : Reynold's analogy states that (where, St = Stanton number f = friction factor) (A) St = f/2 (B) St = f/4 (C) St = 4f (D) St = f 1/2

Last Answer : (A) St = f/2

A large Reynold number is indication of (A) Smooth and streamline flow (B) Laminar flow (C) Steady flow (D) Highly turbulent flow

Description : A large Reynold number is indication of (A) Smooth and streamline flow (B) Laminar flow (C) Steady flow (D) Highly turbulent flow

Last Answer : Answer: Option D

Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will (A) Increase (B) Decrease (C) Remain same (D) Data insufficient to predict pressure drop

Description : Reynolds number for water flow through a tube of I.D. 5 cm is 1500. If a liquid of 5 centipoise viscosity and 0.8 specific gravity flows in the same pipe at the same velocity, then the pressure drop will (A) Increase (B) Decrease (C) Remain same (D) Data insufficient to predict pressure drop

Last Answer : (A) Increase

The value of critical Reynolds number for pipe flow is (A) 1,300(B) 10,000 (C) 100,000 (D) None of these

Description : The value of critical Reynolds number for pipe flow is (A) 1,300 (B) 10,000 (C) 100,000 (D) None of these

Last Answer : (A) 1,300

Reynolds number for flow of water at room temperature through 2 cm dia pipe at an average velocity of 5 cm/sec is around (A) 2000 (B) 10(C) 100 (D) 1000 Answer:

Description : Reynolds number for flow of water at room temperature through 2 cm dia pipe at an average velocity of 5 cm/sec is around (A) 2000 (B) 10 (C) 100 (D) 1000 Answer:

Last Answer : (D) 1000

Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body 3. For smooth surfaces, coefficient of friction depends upon velocity 4. Damping force depends upon the rubbing velocity between two rubbing surfaces a. Only statement 1 b. Statement 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true

Description : Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body ... 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true

Last Answer : c. Only statement 2

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

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 co￾efficient for turbulent flow conditions is proportional to (A) d 0.8 (B) d -0.2 (C) d -1 (D) d -1.8

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 co￾efficient 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

The head loss in turbulent flow in a pipe varies (A) Directly as the velocity (B) Inversely as the square of the velocity (C) Approximately as the square of the velocity (D) Inversely as the square of the diameter

Description : The head loss in turbulent flow in a pipe varies (A) Directly as the velocity (B) Inversely as the square of the velocity (C) Approximately as the square of the velocity (D) Inversely as the square of the diameter

Last Answer : (C) Approximately as the square of the velocity

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

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