Water hammer is caused, when water flowing in a pipe is suddenly brought to rest by closing the valve. The extent of pressure thus produced due to water hammer depends on the (A) Pipe length (B) Fluid velocity in the pipe (C) Time taken to close the valve (D) All (A), (B) and (C)

Water hammer is caused, when water flowing in a pipe is suddenly
brought to rest by closing the valve. The extent of pressure thus produced
due to water hammer depends on the
(A) Pipe length
(B) Fluid velocity in the pipe
(C) Time taken to close the valve
(D) All (A), (B) and (C)
by

1 Answer

Answer :

(D) All (A), (B) and (C)
by

Related questions

The hammer blow in pipes occurs when (A) There is excessive leakage in the pipe (B) The pipe bursts under high pressure of fluid(C) The flow of fluid through the pipe is suddenly brought to rest by closing of the valve (D) The flow of fluid through the pipe is gradually brought to rest by closing of the valve

Description : The hammer blow in pipes occurs when (A) There is excessive leakage in the pipe (B) The pipe bursts under high pressure of fluid (C) The flow of fluid through the pipe is suddenly brought to ... valve (D) The flow of fluid through the pipe is gradually brought to rest by closing of the valve

Last Answer : Answer: Option C

Pick up the correct statement from the following: (A) The internal pressure within a pipe, is caused due to water head and hammer pressure (B) In pressure pipes with water at rest, the pressure is equal to water head (C) Sudden closure of a valve, causes the water hammer pressure (D) All the above

Description : Pick up the correct statement from the following:  (A) The internal pressure within a pipe, is caused due to water head and hammer pressure  (B) In pressure pipes with water at rest, the pressure ... (C) Sudden closure of a valve, causes the water hammer pressure  (D) All the above 

Last Answer : (D) All the above 

The magnitude of water hammer depends upon the (A) Elastic properties of the pipe material (B) Elastic properties of the liquid flowing through the pipe (C) Speed at which the valve is closed (D) All of the above

Description : The magnitude of water hammer depends upon the (A) Elastic properties of the pipe material (B) Elastic properties of the liquid flowing through the pipe (C) Speed at which the valve is closed (D) All of the above

Last Answer : Answer: Option D

Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation (B) Cavitation may be caused due to boiling of liquid by decreasing the pressure resulting in formation & collapse of vapor cavities (C) Cavitation begins at higher static pressure and lower velocity in larger diameter pipelines resulting in audible noise(D) Large scale cavitation cannot damage pipeline, restrict fluid flow anddamage steam turbine blades

Description : Pick out the wrong statement about cavitation. (A) Sudden reduction of pressure in a fluid flow system caused by flow separation, vortex formation or abrupt closing of valve leads to cavitation ... (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

Last Answer : (D) Large scale cavitation cannot damage pipeline, restrict fluid flow and damage steam turbine blades

In a pressure penstock 4500 m long, water is flowing at a velocity of 4 m/s. If the velocity of the pressure wave traveling in the pipe, due sudden complete closure of a valve at the downstream end, is given as 1500 m/s, what would be the period of oscillation in second under frictionless conditions? (a) 6 (b) 8 (c) 9 (d) 11

Description : In a pressure penstock 4500 m long, water is flowing at a velocity of 4 m/s. If the velocity of the pressure wave traveling in the pipe, due sudden complete closure of a valve at the downstream end, is ... period of oscillation in second under frictionless conditions? (a) 6 (b) 8 (c) 9 (d) 11

Last Answer : (a) 6

he pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe at the same flow rate/average velocity, then the pressure drop in this case will be (A) Δp (B) 2Δp (C) Δp 2 (D) Δp/2

Description : he pressure drop per unit length of pipe incurred by a fluid 'X' flowing through pipe is Δp. If another fluid 'Y' having both the specific gravity & density just double of that of fluid 'X', flows through the same pipe ... then the pressure drop in this case will be (A) Δp (B) 2Δp (C) Δp 2 (D) Δp/2

Last Answer : (B) 2Δp

Water flowing at a 6m/s through a 60 mm pipe is suddenly channeled into a 30 mm pipe. What is the velocity in the small pipe?  a. 34m/s  b. 24m/s  c. 15m/s  d. 27m/s

Description : Water flowing at a 6m/s through a 60 mm pipe is suddenly channeled into a 30 mm pipe. What is the velocity in the small pipe?  a. 34m/s  b. 24m/s  c. 15m/s  d. 27m/s

Last Answer : 24m/s

The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is (A) Parabolic (B) Flat (C) Flat near the wall and parabolic in the middle (D) Parabolic near the wall and flat in the middle

Description : The velocity profile for a Bingham plastic fluid flowing (under laminar conditions) in a pipe is (A) Parabolic (B) Flat (C) Flat near the wall and parabolic in the middle (D) Parabolic near the wall and flat in the middle

Last Answer : (D) Parabolic near the wall and flat in the middle

essure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as (A) V1.8 (B) V-0.2 (C) V2.7 (D) V

Description : essure drop (Δp) for a fluid flowing in turbulent flow through a pipe is a function of velocity (V) as (A) V1.8 (B) V-0.2 (C) V2.7 (D) V

Last Answer : (D) V

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

Critical time for developing a water hammer, is the time required for (A) Closing the valve (B) The wave to travel from valve to the reservoir (C) The wave to travel from the valve to the reservoir and back (D) None of these

Description : Critical time for developing a water hammer, is the time required for  (A) Closing the valve  (B) The wave to travel from valve to the reservoir  (C) The wave to travel from the valve to the reservoir and back  (D) None of these 

Last Answer : (C) The wave to travel from the valve to the reservoir and back 

19. The water hammer in pipes occurs due to sudden change in the velocity of flowing liquid A) Agree B) Disagree

Description : 19. The water hammer in pipes occurs due to sudden change in the velocity of flowing liquid A) Agree B) Disagree

Last Answer : A

A ball tied with a string to a rotating shaft revolves at uniform speed. As the shaft is suddenly brought to rest, the string starts getting round the shaft with the angular velocity of the ball (a) increasing (b) decreasing (c) remaining constant (d) becoming zero

Description : A ball tied with a string to a rotating shaft revolves at uniform speed. As the shaft is suddenly brought to rest, the string starts getting round the shaft with the angular velocity of the ball (a) increasing (b) decreasing (c) remaining constant (d) becoming zero

Last Answer : Ans:(a)

The Bernoulli's equation is based on the assumption that (A) There is no loss of energy of the liquid flowing (B) The velocity of flow is uniform across any cross-section of the pipe (C) No force except gravity acts on the fluid (D) All of the above

Description : The Bernoulli's equation is based on the assumption that (A) There is no loss of energy of the liquid flowing (B) The velocity of flow is uniform across any cross-section of the pipe (C) No force except gravity acts on the fluid (D) All of the above

Last Answer : Answer: Option D

Water hammer in a pipeline results from the (A) Bursting of pipelines due to closure by a valve (B) Rapid pressure change due to a rapid change in the rate of flow (C) Pressure increase due to closure of a valve resulting in decrease in rate of flow (D) None of these

Description : Water hammer in a pipeline results from the (A) Bursting of pipelines due to closure by a valve (B) Rapid pressure change due to a rapid change in the rate of flow (C) Pressure increase due to closure of a valve resulting in decrease in rate of flow (D) None of these

Last Answer : (B) Rapid pressure change due to a rapid change in the rate of flow

Which of the following factors does not contribute to the pressure drop in a pipeline? (A) Velocity of fluid (B) Size of pipe (C) Length of pipe and number of bends (D) None of these

Description : Which of the following factors does not contribute to the pressure drop in a pipeline? (A) Velocity of fluid (B) Size of pipe (C) Length of pipe and number of bends (D) None of these

Last Answer : (D) None of these

For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Description : For laminar flow of Newtonian fluids through a circular pipe, for a given pressure drop and length & diameter of pipe, the velocity of fluid is proportional to (where, μ = fluid viscosity ) (A) μ (B) 1/μ (C) √μ (D) 1/√μ

Last Answer : (B) 1/μ

For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is (A) More (B) Less (C) Equal (D) Either (A) or (B); depends on the viscosity of the fluid

Description : For the same terminal conditions and valve size, the pressure drop in a fully opened globe valve as compared to that in a gate valve is (A) More (B) Less (C) Equal (D) Either (A) or (B); depends on the viscosity of the fluid

Last Answer : (A) More

At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be (A) Minimum (B) Maximum (C) Zero (D) Could be any value

Description : At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be (A) Minimum (B) Maximum (C) Zero (D) Could be any value

Last Answer : Answer: Option D

A pitot tube is used to measure the (A) Velocity of flow at the required point in a pipe (B) Pressure difference between two points in a pipe (C) Total pressure of liquid flowing in a pipe (D) Discharge through a pipe

Description : A pitot tube is used to measure the (A) Velocity of flow at the required point in a pipe (B) Pressure difference between two points in a pipe (C) Total pressure of liquid flowing in a pipe (D) Discharge through a pipe

Last Answer : Answer: Option A

Venturimeter is used to (A) Measure the velocity of a flowing liquid (B) Measure the pressure of a flowing liquid (C) Measure the discharge of liquid flowing in a pipe (D) Measure the pressure difference of liquid flowing between two points in a pipe line

Description : Venturimeter is used to (A) Measure the velocity of a flowing liquid (B) Measure the pressure of a flowing liquid (C) Measure the discharge of liquid flowing in a pipe (D) Measure the pressure difference of liquid flowing between two points in a pipe line

Last Answer : Answer: Option C

The difference in the reservoir level and the lowest point of the water mains is 180 m. The expected pressure due to water hammer is 7.5 kg/cm2 in a pressure conduit of diameter 1 m. Assuming the efficiency of the riveted joints of the pipe as 0.6 and minimum cover 3 mm for corrosion, the thickness of the pipe materials, is (A) 10 mm (B) 15 mm (C) 20 mm (D) 25 mm

Description : The difference in the reservoir level and the lowest point of the water mains is 180 m. The  expected pressure due to water hammer is 7.5 kg/cm2  in a pressure conduit of diameter 1 m.  Assuming the efficiency of the ... , is  (A) 10 mm  (B) 15 mm  (C) 20 mm  (D) 25 mm 

Last Answer : (C) 20 mm

The purpose of a surge tank is (A) To control the pressure variations due to rapid changes in the pipe line flow (B) To eliminate water hammer possibilities (C) To regulate flow of water to turbines by providing necessary retarding head of water (D) All of the above

Description : The purpose of a surge tank is (A) To control the pressure variations due to rapid changes in the pipe line flow (B) To eliminate water hammer possibilities (C) To regulate flow of water to turbines by providing necessary retarding head of water (D) All of the above

Last Answer : Answer: Option D

Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is (A) 0.1 (B) > 1 (C) < 1 (D) 1

Description : Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is (A) 0.1 (B) > 1 (C) < 1 (D) 1

Last Answer : (A) 0.1

At Pr > 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the (A) Buffer zone (B) Turbulent core (C) Both (A) and (B) (D) Viscous sub-layer

Description : At Pr > 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the (A) Buffer zone (B) Turbulent core (C) Both (A) and (B) (D) Viscous sub-layer

Last Answer : (D) Viscous sub-layer

Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000

Last Answer : (D) > 10000

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

Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is (A) 0.2 (B) 0.4 (C) 0.6 (D) 0.8

Description : Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is (A) 0.2 (B) 0.4 (C) 0.6 (D) 0.8

Last Answer : (C) 0.6

The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Description : The characteristic dimensionless groups for heat transfer to a fluid flowing through a pipe in laminar flow are (A) Re.Gz (B) Nu, Pr (C) Nu, Pr, Re (D) Nu, Gz

Last Answer : (D) Nu, Gz

At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated pipe? (A) 0.5 (B) < 0.5 (C) > 0.6 (D) < 0.1

Description : At what value of Prandtl number, conduction is negligible in the turbulent core of a fluid flowing through a heated pipe? (A) 0.5 (B) < 0.5 (C) > 0.6 (D) < 0.1

Last Answer : (C) > 0.6

Shear stress in a fluid flowing in a round pipe (A) Varies parabolically across the cross-section(B) Remains constant over the cross-section(C) Is zero at the centre and varies linearly with the radius(D) Is zero at the wall and increases linearly to the centre

Description : Shear stress in a fluid flowing in a round pipe (A) Varies parabolically across the cross-section (B) Remains constant over the cross-section (C) Is zero at the centre and varies linearly with the radius (D) Is zero at the wall and increases linearly to the centre

Last Answer : (C) Is zero at the centre and varies linearly with the radius

Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on the initial velocity ( v 0 ) and the braking capacity, or deceleration, ?a that is caused by the braking. A car travelling at speed 72km/hr suddenly applies the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science

Description : Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on ... the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science

Last Answer : Here u=72 km/hr = 72×10003600m/s=2072×10003600m/s=20 m/s , v=0 a= -5 m/s2 Now using the relation v2=u2+2asv2=u2+2as 0=(20)2+2×(−5)×s0=(20)2+2×(−5)×s s=40ms=40m

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

The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32

Description : The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v w = Specific weight of the flowing liquid) (A) 4 (B) 8 (C) 16 (D) 32

Last Answer : Answer: Option D

A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is (A) 20 m/sec (B) 10 m/sec (C) 5 √2 m/sec (D) 5 m/sec

Description : A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is (A) 20 m/sec (B) 10 m/sec (C) 5 √2 m/sec (D) 5 m/sec

Last Answer : (B) 10 m/sec

Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to (A) Reynold stresses (B) Shear forces (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to (A) Reynold stresses (B) Shear forces (C) Both (A) & (B) (D) Neither (A) nor (B)

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

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

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

Pressure gradient in the pipe flow is influenced by the (A) Diameter of pipe (B) Velocity of the fluid (C) Density & viscosity of the fluid (D) All (A), (B) and (C)

Description : Pressure gradient in the pipe flow is influenced by the (A) Diameter of pipe (B) Velocity of the fluid (C) Density & viscosity of the fluid (D) All (A), (B) and (C)

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

The fluid velocity varies as the cube of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop for __________ fluid. (A) Newtonian (B) Pseudo-plastic (C) Dilatent (D) Bingham plastic

Description : The fluid velocity varies as the cube of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop for __________ fluid. (A) Newtonian (B) Pseudo-plastic (C) Dilatent (D) Bingham plastic

Last Answer : (B) Pseudo-plastic

The fluid velocity varies as the square of the cylindrical pipe diameter, in case of steady state laminar flow at constant pressure drop, for __________ fluid. (A) Newtonian (B) Dilatant (C) Pseudo-plastic (D) Non-Newtonian

Description : The fluid velocity varies as the square of the cylindrical pipe diameter, in case of steady state laminar flow at constant pressure drop, for __________ fluid. (A) Newtonian (B) Dilatant (C) Pseudo-plastic (D) Non-Newtonian

Last Answer : (A) Newtonian

The fluid velocity varies as the square root of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop of __________ fluid. (A) Dilatent (B) Pseudo-plastic (C) Bingham plastic (D) Newtonian

Description : The fluid velocity varies as the square root of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop of __________ fluid. (A) Dilatent (B) Pseudo-plastic (C) Bingham plastic (D) Newtonian

Last Answer : (A) Dilatent

The pressure of fluid due to hammer blow is (A) Directly proportional to density of fluid (B) Inversely proportional to density of fluid (C) Directly proportional to (density)1/2 of fluid (D) Inversely proportional to (density)1/2 of fluid

Description : The pressure of fluid due to hammer blow is (A) Directly proportional to density of fluid (B) Inversely proportional to density of fluid (C) Directly proportional to (density)1/2 of fluid (D) Inversely proportional to (density)1/2 of fluid

Last Answer : Answer: Option C

Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter(B) A Venturimeter with a given gage difference discharges at a greater rate,when the flow is vertically downward through it, than when the flow is verticallyupward(C) For a given pressure difference, the discharge of gas is greater through aVenturimeter, when compressibility is taken into account, than when it isneglected(D) The overall pressure loss is the same in a given pipe line, whether aVenturimeter or a nozzle with the same throat dia is used

Description : Sele(A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meterct the correct statement. (B) A Venturimeter with a given gage difference discharges at a ... a given pipe line, whether a Venturimeter or a nozzle with the same throat dia is used

Last Answer : (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meterct the correct statement

Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter(B) A Venturimeter with a given gage difference discharges at a greater rate,when the flow is vertically downward through it, than when the flow is verticallyupward(C) For a given pressure difference, the discharge of gas is greater through aVenturimeter, when compressibility is taken into account, than when it isneglected(D) The overall pressure loss is the same in a given pipe line, whether aVenturimeter or a nozzle with the same throat dia is used

Description : Select the correct statement. (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter (B) A Venturimeter with a given gage difference discharges at a ... a given pipe line, whether a Venturimeter or a nozzle with the same throat dia is used

Last Answer : (A) The discharge through a Venturimeter depends upon Δp only and isindependent of orientation of the meter

Deformation drag, which is caused by widespread deformation of fluid around the immersed body(A) Occurs when NReis very small(B) Is primarily a friction drag(C) Is independent of body length(D) Depends mainly on cross-sectional shape

Description : Deformation drag, which is caused by widespread deformation of fluid around the immersed body (A) Occurs when NRe is very small (B) Is primarily a friction drag (C) Is independent of body length (D) Depends mainly on cross-sectional shape

Last Answer : (A) Occurs when NRe is very small