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

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
by

1 Answer

Answer :

Answer: Option C
by

Related questions

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)

Description : 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)

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

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

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 

Pipes are laid parallel (A) To increase the capacity of the water supply (B) To provide a means of repairing without closing water supply (C) To meet the requirement of excessive supply (D) All the above

Description : Pipes are laid parallel (A) To increase the capacity of the water supply (B) To provide a means of repairing without closing water supply (C) To meet the requirement of excessive supply (D) All the above

Last Answer : (D) All the above

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

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

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

Two pipe P & Q fill a tab in 5 hrs and 20 hrs respectively. If both the pipes are open then due to the leakage, it took 30mins more to fill the tab. If the tab is full, how long will it take for the leakage alone to empty the tank? A) 28 B) 24 C) 36 D) 12

Description : Two pipe P & Q fill a tab in 5 hrs and 20 hrs respectively. If both the pipes are open then due to the leakage, it took 30mins more to fill the tab. If the tab is full, how long will it take for the leakage alone to empty the tank? A) 28 B) 24 C) 36 D) 12

Last Answer : C Part filled by(P+Q) in 1 hr = 1/5 + 1/20 = ¼ So P & Q together can fill the tank in 4 hrs. Work done by the leak in 1 hr = 1 / 4 - 2/9 Leak will empty the tank in 36 hrs.

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

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

Actual lift of a pump is always less than the theoretical lift and is limited by the (A) Specific gravity & temperature of the liquid (B) Leakage & pressure decreasing at higher elevations (C) Frictional resistance through pipes, fittings & passages (D) All (A), (B) and (C)

Description : Actual lift of a pump is always less than the theoretical lift and is limited by the (A) Specific gravity & temperature of the liquid (B) Leakage & pressure decreasing at higher elevations (C) Frictional resistance through pipes, fittings & passages (D) All (A), (B) and (C)

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

The valves provided at low points of pipes to drain off water quickly under gravity, are called (A) Blow off valves (B) Drain valves (C) Sewer valves (D) All the above

Description : The valves provided at low points of pipes to drain off water quickly under gravity, are called (A) Blow off valves (B) Drain valves (C) Sewer valves (D) All the above

Last Answer : (D) All the above

Choking in case of pipe flow means that a (A) Specified mass flow rate cannot be achieved (B) Valve is closed in the line (C) Restriction in flow cross-section area occurs (D) None of these

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Last Answer : (B) Valve is closed in the line

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

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The maximum pressure which the pipe can withstand without any leakage during hydrostatic pressure test, is called (A) Working pressure (B) Design pressure (C) Test pressure (D) Hydrostatic pressure

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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

A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if (A) Length of both the pipes is same (B) Diameter of both the pipes is same (C) Loss of head and discharge of both the pipes is same (D) Loss of head and velocity of flow in both the pipes is same

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Last Answer : Answer: Option C

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

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A pile is being driven with a drop hammer weighing 1800 kg and having a free fall of 1.00 m. If the penetration with last blow is 5 mm, the load carrying capacity of the pile, -according to the Engineering News formula, is (A) 100 tonnes (B) 50 tonnes (C) 20 tonnes (D) 10 tonnes

Description : A pile is being driven with a drop hammer weighing 1800 kg and having a free fall of 1.00 m. If the penetration with last blow is 5 mm, the load carrying capacity of the pile, -according to the Engineering News formula, is (A) 100 tonnes (B) 50 tonnes (C) 20 tonnes (D) 10 tonnes

Last Answer : (D) 10 tonnes

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

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Last Answer : (C) 20 mm

Purpose of relief valve in a reciprocating pump is to (A) Protect the pump against developing excessive pressure (B) Facilitate unidirectional flow of liquid (C) Reduce the discharge pressure (D) Control the rate of discharge

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Last Answer : (A) Protect the pump against developing excessive pressure

A cycle tyre bursts suddenly. This represents an – (1) Isothermal process (2) Adiabatic process (3) Isochoric process (4) Isoboric process

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Last Answer : (2) Adiabatic process Explanation: When a tyre bursts suddenly energy is not immediately transferred between the system and the surrounding. So the process is adiabatic. There sudden expansion of its air ... tyre is cooled. In adiabatic process, heat neither enters the system nor leaves the system.

A cycle type bursts suddenly. This represent an

Description : A cycle type bursts suddenly. This represent an

Last Answer : Isothermal Process

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Last Answer : Adiabatic process

Runoff is the quantity of water which flows (A) In sewer pipes (B) Due to leakage in pipes (C) In rivers (D) None of these

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Last Answer : (C) In rivers

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

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Last Answer : Ans:(a)

In case of end to end connection of two or more pipes in series, the __________ each pipe.(A) Same rate of flow passes through (B) Head loss is same through (C) Rate of flow in each pipe is proportional to the length of (D) Total flow rate is the sum of flow rate in

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The ratio of the stresses produced by a suddenly applied load and by a gradually applied load on a bar, is (A) 1/4 (B) 1/2 (C) 1 (D) 2

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Last Answer : (D) 2 

The maximum stress intensity due to a suddenly applied load is x-times the stress intensity produced by the load of the same magnitude applied gradually. The value of x is (A) 1 (B) 2 (C) 3 (D) 1/2

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Last Answer : (B) 2

During the opening of a valve in a pipe line, the flow is (A) Steady (B) Unsteady (C) Uniform (D) Laminar

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Last Answer : Answer: Option B

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Last Answer : (b) 1 & 3 only

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

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How long should the rest period be between anaerobic bursts of exercises?

Description : How long should the rest period be between anaerobic bursts of exercises?

Last Answer : Brief;Less than 2 minutes sometimes

A storm is predicted if atmospheric pressure – (1) Rises suddenly (2) Rises gradually (3) Falls suddenly (4) Falls gradually

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Description : A storm is predicted if atmospheric pressure (1) rises suddenly (2) rises gradually (3) falls suddenly (4) falls gradually

Last Answer :  falls suddenly

Stress under suddenly applied load is (a) Three times than the gradually applied load (b) equal to the that due to gradually applied load (c) Less than that due to gradually applied load (d) none

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Last Answer : (B) At summits 

Barometer is used to measure (A) Velocity of liquid(B) Atmospheric pressure (C) Pressure in pipes and channels (D) Difference of pressure between two points in a pipe

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Last Answer : Answer: Option B

A differential manometer is used to measure (A) Atmospheric pressure (B) Pressure in pipes and channels (C) Pressure in Venturimeter (D) Difference of pressures between two points in a pipe

Description : A differential manometer is used to measure (A) Atmospheric pressure (B) Pressure in pipes and channels (C) Pressure in Venturimeter (D) Difference of pressures between two points in a pipe

Last Answer : Answer: Option D

A manometer is used to measure (A) Atmospheric pressure (B) Pressure in pipes and channels (C) Pressure in Venturimeter (D) Difference of pressures between two points in a pipe

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Last Answer : Answer: Option B

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

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 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

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Last Answer : (C) < 1

The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe) (A) A (B) D (C) 1/A (D) 1/A2

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Last Answer : (C) 1/A

A fuse will 'blow' if _____________. A. an electric motor is stopped suddenly by opening a switch B. the flow of current to the protection device is reversed C. the electrical current exceeds the rated value of the fuse D. unequal resistors are connected in parallel

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Gradually varying fluid flow is an example of __________ flow. (A) Non-steady uniform (B) Non-steady non-uniform (C) Steady uniform (D) Steady non-uniform

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Last Answer : (A) Non-steady uniform

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

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Last Answer : Answer: Option C