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

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
by

1 Answer

Answer :

(C) Reynold number, relative roughness and head loss
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

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

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)

. 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

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

Description : 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

Last Answer : (A) Depends only on Reynolds number

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 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

The losses in open channel flow generally vary as the (A) Inverse of the roughness (B) First power of the roughness (C) Square of the velocity (D) Inverse square of hydraulic radius

Description : The losses in open channel flow generally vary as the (A) Inverse of the roughness (B) First power of the roughness (C) Square of the velocity (D) Inverse square of hydraulic radius

Last Answer : (B) First power of the roughness

Hydraulic diameter for non-circular ducts is equal to __________ times the area of flow divided by the perimeter. (A) Two (B) Three (C) Four (D) Eight

Description : Hydraulic diameter for non-circular ducts is equal to __________ times the area of flow divided by the perimeter. (A) Two (B) Three (C) Four (D) Eight

Last Answer : (C) Four

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

The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number) (A) 1/RN (B) 4/RN (C) 16/RN (D) 64/RN

Description : The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number) (A) 1/RN (B) 4/RN (C) 16/RN (D) 64/RN

Last Answer : Answer: Option C

The equation relating friction factor to Reynold number, f -0.5 = 4 loge (NRe /√f) -0.4 , is called the __________ equation. (A) Nikuradse (B) Von-Karman

Description : The equation relating friction factor to Reynold number, f -0.5 = 4 loge (NRe /√f) -0.4 , is called the __________ equation. (A) Nikuradse (B) Von-Karman

Last Answer : (B) Ergun's

The ratio of the hydraulic radius to the diameter of the channel, for maximum mean velocity of flow in a circular channel, in open channel flow is (A) 0.3 (B) 0.9 (C) 0.03 (D) 0.66

Description : The ratio of the hydraulic radius to the diameter of the channel, for maximum mean velocity of flow in a circular channel, in open channel flow is (A) 0.3 (B) 0.9 (C) 0.03 (D) 0.66

Last Answer : (A) 0.3

In Chezy’s formula V = C rs for calculating the velocity of flow in circular sewer of diameter running full, the value of hydraulic mean radius is A. D B. D /2 C. D/3 D. D/4

Description : In Chezy’s formula V = C rs for calculating the velocity of flow in circular sewer of diameter running full, the value of hydraulic mean radius is A. D B. D /2 C. D/3 D. D/4

Last Answer : ANS: D

Which of the following two quantities when same, makes one pipe system equivalent to another pipe system? (A) Head & discharge(B) Length & discharge(C) Length & diameter(D) Friction factor & diameter

Description : Which of the following two quantities when same, makes one pipe system equivalent to another pipe system? (A) Head & discharge (B) Length & discharge (C) Length & diameter (D) Friction factor & diameter

Last Answer : (A) Head & discharge

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

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

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

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)

Two pipe systems can be said to be equivalent, when the following quantities are same (A) Friction loss and flow (B) Length and diameter (C) Flow and length (D) Friction factor and diameter

Description : Two pipe systems can be said to be equivalent, when the following quantities are same (A) Friction loss and flow (B) Length and diameter (C) Flow and length (D) Friction factor and diameter

Last Answer : Answer: Option A

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

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

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

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 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

The lens equation 1/f = 1/ + 1/ is applicable (A) When the thickness of the lens is small (B) Only to conjugate distances along the principal axis (C) The computed quantities are accurate enough for geometrical optics of simple distances (D) All the above

Description : The lens equation 1/f = 1/ + 1/ is applicable (A) When the thickness of the lens is small (B) Only to conjugate distances along the principal axis (C) The computed quantities are accurate enough for geometrical optics of simple distances (D) All the above

Last Answer : (D) All the above

Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b

Description : Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b

Last Answer : (B) Mean velocity

Hydraulic mean radius is A. Mean radius of sewer B. Difference in heads between two points in circular pipes C. Mean of radii in a pipe line of varying cross -sections D. Cross-sectional area/wetted perimeter

Description : Hydraulic mean radius is A. Mean radius of sewer B. Difference in heads between two points in circular pipes C. Mean of radii in a pipe line of varying cross -sections D. Cross-sectional area/wetted perimeter

Last Answer : ANS: D

The velocity corresponding to Reynold number of 2000 is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Description : The velocity corresponding to Reynold number of 2000 is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Last Answer : Answer: Option C

The velocity corresponding to Reynold number of 2800, is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Description : The velocity corresponding to Reynold number of 2800, is called (A) Sub-sonic velocity (B) Super-sonic velocity (C) Lower critical velocity (D) Higher critical velocity

Last Answer : Answer: Option D

In a flow net (A) Flow lines and equipotential lines cross each other at right angles (B) Fields are rectangles whose length is twice the breadth (C) Smaller the dimensions of the field, smaller will be the hydraulic gradient and velocity of flow through it (D) For homogeneous soil, the curves are smooth and circular

Description : In a flow net (A) Flow lines and equipotential lines cross each other at right angles (B) Fields are rectangles whose length is twice the breadth (C) Smaller the dimensions of the field, ... gradient and velocity of flow through it (D) For homogeneous soil, the curves are smooth and circular

Last Answer : Option A

Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the centre of the pipe. 4. Hydraulic gradient varies as the square of the mean velocity of flow. Which of these statements are correct? (a) 1, 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Description : Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the ... 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only

Last Answer : (b) 1 & 3 only

According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe) (A) flv²/2gd (B) flv²/gd (C) 3flv²/2gd (D) 4flv²/2gd

Description : According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe) (A) flv²/2gd (B) flv²/gd (C) 3flv²/2gd (D) 4flv²/2gd

Last Answer : Answer: Option D

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

A cyclist moves uniformaly on a horizontal circular track of radius 100 m . If the cofficient of friction is 0.1. At which of the following speed (s)

Description : A cyclist moves uniformaly on a horizontal circular track of radius 100 m . If the cofficient of friction is 0.1. At which of the following speed (s)

Last Answer : A cyclist moves uniformaly on a horizontal circular track of radius 100 m . If the cofficient of friction is 0.1. ... m/s C. 14 m/s D. none of these

The hydraulic mean depth or the hydraulic radius is the ratio of (A) Area of flow and wetted perimeter (B) Wetted perimeter and diameter of pipe (C) Velocity of flow and area of flow (D) None of these

Description : The hydraulic mean depth or the hydraulic radius is the ratio of (A) Area of flow and wetted perimeter (B) Wetted perimeter and diameter of pipe (C) Velocity of flow and area of flow (D) None of these

Last Answer : Answer: Option A

26. Air velocity in ducts can be measured by using and manometer a) Orifice meter b) Borden gauge c) Pitot tube d) Anemometer

Description : Air velocity in ducts can be measured by using and manometer a) Orifice meter b) Borden gauge c) Pitot tube d) Anemometer

Last Answer : Pitot tube

In case of laminar flow of fluid through a circular pipe, the (A) Shear stress over the cross-section is proportional to the distance from the surface of the pipe (B) Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder (C) Velocity profile varies hyperbolically and the shear stress remains constant over the cross-section (D) Average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)

Description : In case of laminar flow of fluid through a circular pipe, the (A) Shear stress over the cross-section is proportional to the distance from the surface of the pipe (B) Surface of velocity distribution is a ... occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)

Last Answer : (B) Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder

Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will (A) Increase (B) Decrease (C) Remain unchanged (D) Data insufficient to predict relative pressure drop

Description : Two fluids are flowing through two similar pipes of the same diameter. The Reynold's number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the ... (A) Increase (B) Decrease (C) Remain unchanged (D) Data insufficient to predict relative pressure drop

Last Answer : (B) Decrease

The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which ‘D’ is the diffusivity of solute, is (A) D/a (B) D/2a (C) Proportional to √D (D) Dependent on the Reynolds number

Description : The mass transfer co-efficient for a solid sphere of radius 'a' dissolving in a large volume of quiescent liquid, in which ‘D’ is the diffusivity of solute, is (A) D/a (B) D/2a (C) Proportional to √D (D) Dependent on the Reynolds number

Last Answer : (D) Dependent on the Reynolds number

Experimental study of laminar fluid flow through a circular tube was conducted by(A) Reynolds(B) Hagen and Poiseuille(C) Pascal(D) Blake-Plummer

Description : Experimental study of laminar fluid flow through a circular tube was conducted by (A) Reynolds (B) Hagen and Poiseuille (C) Pascal (D) Blake-Plummer

Last Answer : (B) Hagen and Poiseuille

How does channel roughness influence river velocity?

Description : How does channel roughness influence river velocity?

Last Answer : These obstacles causes friction between water and rocks.This ultimately reduces the velocity of river water.The more roughness of the channel, the less the river`s velocity.

The total energy line lies over the hydraulic gradient line by an amount equal to the (A) Pressure head (B) Velocity head (C) Pressure head + velocity head (D) Pressure head - velocity head

Description : The total energy line lies over the hydraulic gradient line by an amount equal to the (A) Pressure head (B) Velocity head (C) Pressure head + velocity head (D) Pressure head - velocity head

Last Answer : Answer: Option B

The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the (A) Pressure head(B) Velocity head (C) Pressure head + velocity head (D) Pressure head - velocity head

Description : The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the (A) Pressure head (B) Velocity head (C) Pressure head + velocity head (D) Pressure head - velocity head

Last Answer : Answer: Option A

In case of Venturimeter, friction losses are about __________ percent of maximum velocity head. (A) 2 (B) 8 (C) 12 (D) 20

Description : In case of Venturimeter, friction losses are about __________ percent of maximum velocity head. (A) 2 (B) 8 (C) 12 (D) 20

Last Answer : (A) 2

Work done by a body of mass 100 kg moving along a circular path of radius 2 m with a uniform velocity of 10 m/sec is a.5000 J b.2500 J c.509.68 J d.None of the above e.Tapered bearing

Description : Work done by a body of mass 100 kg moving along a circular path of radius 2 m with a uniform velocity of 10 m/sec is a.5000 J b.2500 J c.509.68 J d.None of the above e.Tapered bearing

Last Answer : d. None of the above

An artificial satellite is moving in a circular orbit of radius 42.250 km (approx). Calculate its linear velocity if takes 24 hour to revolve around earth.? -Science

Description : An artificial satellite is moving in a circular orbit of radius 42.250 km (approx). Calculate its linear velocity if takes 24 hour to revolve around earth.? -Science

Last Answer : Given r =42.250 km , T= 24 hour Linear velocity in circular motion is given by v=2πrT=2×3.14×42.25024=11.05km/hrv=2πrT=2×3.14×42.25024=11.05km/hr

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