Hydraulics & Fluid Mechanics objective question and answer
Question No. 301
Viscosity of water in comparison to mercury is
(A) Higher
(B) Lower
(C) Same
(D) Higher/lower depending on temperature
Answer: Option A
Question No. 302
The power transmitted through the pipe is maximum when the head lost due to friction is equal to
(A) One-fourth of the total supply head
(B) One-third of the total supply head
(C) One-half of the total supply head
(D) Two-third of the total supply head
Answer: Option B
Question No. 303
Falling drops of water become spheres due to the property of
(A) Adhesion
(B) Cohesion
(C) Surface tension
(D) Viscosity
Answer: Option C
Question No. 304
A hemispherical tank of radius (R) has an orifice of cross-sectional area (a) at its bottom and is full
of liquid. The time required to empty the tank completely is
(A) 1/2/15Cd × a√(2g)
(B) 3/2/15Cd × a√(2g)
(C) 5/2/15Cd × a√(2g)
(D) 7/2/15Cd × a√(2g)
Answer: Option C
Question No. 305
The difference of pressure between the inside and outside of a liquid drop is
(A) p = T × r
(B) p = T/r
(C) p = T/2r
(D) p = 2T/r
Answer: Option D
Question No. 306
A venturi-flume is used to measure
(A) Pressure of liquid
(B) Discharge of liquid
(C) Pressure difference between two points in a channel
(D) Pressure difference between two points in a pipe
Answer: Option B
Question No. 307
Working principle of dead weight pressure gauge tester is based on
(A) Pascal's law
(B) Dalton's law of partial pressure
(C) Newton's law of viscosity
(D) Avogadro's hypothesis
Answer: Option A
Question No. 308
The meatcentric height of a ship is 0.6 m and the radius of gyration is 4 m. The time of rolling of a
ship is
(A) 4.1 s
(B) 5.2 s
(C) 10.4 s
(D) 14.1 s
Answer: Option C
Question No. 309
The discharge through a channel of rectangular section will be maximum, if
(A) Its depth is twice the breadth
(B) Its breadth is twice the depth
(C) Its depth is thrice the breadth
(D) Its breadth is thrice the depth
Answer: Option B
Question No. 310
The discharge through a channel of circular section will be maximum when the depth of water is
__________ the diameter of the circular channel.
(A) 0.34 times
(B) 0.67 times
(C) 0.81 times
(D) 0.95 times
Answer: Option D
Question No. 311
Uniform flow occurs when
(A) The flow is steady
(B) The flow is streamline
(C) Size and shape of the cross section in a particular length remain constant
(D) Size and cross section change uniformly along length
Answer: Option C
Question No. 312
Bulk modulus of a fluid is the ratio of
(A) Shear stress to shear strain
(B) Increase in volume to the viscosity of fluid
(C) Increase in pressure to the volumetric strain
(D) Critical velocity to the viscosity of fluid
Answer: Option C
Question No. 31
The pressure in pascal's at adepth of 1m below the sirface of a body of water will be equal to
(A) 1 Pa
(B) 91 Pa
(C) 981 Pa
(D) 9810 Pa
Answer: Option D
Question No. 314
An average value of coefficient of velocity is
(A) 0.62
(B) 0.76
(C) 0.84
(D) 0.97
Answer: Option D
Question No. 315
A liquid would wet the solid, if adhesion forces as compared to cohesion forces are
(A) Less
(B) More
(C) Equal
(D) Less at low temperature and more at high temperature
Answer: Option B
Question No. 316
When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular
velocity, the pressure
(B) Increases linearly as its radial distance
(C) Increases as the square of the radial distance
(D) Decreases as the square of the radial distance
Answer: Option A
Question No. 317
Property of a fluid by which its own molecules are attracted is called
(A) Adhesion
(B) Cohesion
(C) Viscosity
(D) Compressibility
Answer: Option B
Question No. 318
According to Bazin's formula, the discharge over a rectangular weir is mL2g x H
3/2where m is equal
to
(A) 0.405 + (0.003/H)
(B) 0.003 + (0.405/H)
(C) 0.405 + (H/0.003)
(D) 0.003 + (H/0.405)
Answer: Option A
Question No. 319
Which of the following is the unit of kinematic viscosity?
(A) Pascal
(B) Poise
(C) Stoke
(D) Faraday
Answer: Option C
Question No. 320
The length AB of a pipe ABC in which the liquid is flowing has diameter (d1) and is suddenly contracted to diameter (d2) at B which is constant for the length BC. The loss of head due to sudden contraction, assuming coefficient of contraction as 0.62, is
A. v₁²/2g
B. v₂²/2g
C. 0.5 v₁²/2g
D. 0.375 v₂²/2g
Answer: Option D
Question No. 321
Operation of McLeod gauge used for low pressure measurement is based on the principle of
(A) Gas law
(B) Boyle's law
(C) Charles law
(D) Pascal's law
Answer: Option B
Question No. 322
Reynold's number is the ratio of the inertia force to the
(A) Surface tension force
(B) Viscous force
(C) Gravity force
(D) Elastic force
Answer: Option B
Question No. 323
A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific
gravity is
(A) 1
(B) 5
(C) 7
(D) 6
Answer: Option D
Question No. 324
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
Answer: Option D
Question No. 325
In a lock-gate, the reaction between two gates is (where P = Resultant pressure on the lock gate, and α = Inclination of the gate with the normal to the side of the lock)
A. p/sinα
B. 2p/sinα
C. p/2sinα
D. 2p/sin (α/2)
Answer: Option C
Question No. 326
In a venturi-flume, the flow takes place at
(A) Atmospheric pressure
(B) Gauge pressure
(C) Absolute pressure
(D) None of these
Answer: Option A
Question No. 327
The normal stress is same in all directions at a point in a fluid
(A) Only when the fluid is frictionless
(B) Only when the fluid is incompressible and has zero viscosity
(C) When there is no motion of one fluid layer relative to an adjacent layer
(D) Irrespective of the motion of one fluid layer relative to an adjacent layer
Answer: Option C
Question No. 328
The highest efficiency is obtained with a channel of __________ section.
(A) Circular
(B) Square
(C) Rectangular
(D) Trapezoidal
Answer: Option D
Question No. 329
A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total
pressure on the wall per unit length is (where w = Specific weight of liquid, and H = Height of
liquid)
(A) wH
(B) wH/2
(C) wH2
/2
(D) wH2
/3
Answer: Option C
Question No. 330
Which of the following manometer has highest sensitivity?
(A) U-tube with water
(B) Inclined U-tube
(C) U-tube with mercury
(D) Micro-manometer with water
Answer: Option D
Question No. 331
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
Answer: Option D
Question No. 332
For a floating body to be in equilibrium
(A) Meta centre should be above e.g.
(B) Centre of buoyancy and e.g. must lie on same vertical plane
(C) A righting couple should be formed
(D) All of the above
Answer: Option D
Question No. 333
When an internal mouthpiece is running free, the discharge through the mouthpiece is (where a =
Area of mouthpiece, and H = Height of liquid above the mouthpiece)
(A) 0.5 a. gH
(B) 0.707 a. gH
(C) 0.855 a. gH
(D) a. gH
Answer: Option A
Question No. 334
A uniform body 3 m long, 2 m wide and 1 m deep floats in water. If the depth of immersion is 0.6
m, then the weight of the body is
(A) 3.53 kN
(B) 33.3 kN
(C) 35.3 kN
(D) None of these
Answer: Option C
Question No. 335
The force per unit length is the unit of
(A) Surface tension
(B) Compressibility
(C) Capillarity
(D) Viscosity
Answer: Option A
Question No. 336
When the Mach number is more than 6, the flow is called
(A) Sub-sonic flow
(B) Sonic flow
(C) Super-sonic flow
(D) Hyper-sonic flow
Answer: Option D
Question No. 337
The upper surface of a weir over which water flows is known is
(A) Crest
(B) Nappy
(C) Sill
(D) Weir top
Answer: Option C
Question No. 338
One cubic metre of water weighs
(A) 100 litres
(B) 250 litres
(C) 500 litres
(D) 1000 litres
Answer: Option D
Question No. 339
Kinematic viscosity is dependent upon
(A) Pressure
(B) Distance
(C) Density
(D) Flow
Answer: Option C
Question No. 340
The discharge through a large rectangular orifice is given by (where H1 = Height of the liquid above
the top of the orifice, H2 = Height of the liquid above the bottom of the orifice, b = Breadth of the
orifice, and Cd = Coefficient of discharge)
(A) Q = (2/3) Cd × b × (2g) × (H2 - H1)
(B) Q = (2/3) Cd × b × (2g) × (H2
1/2 - H1
1/2)
(C) Q = (2/3) Cd × b × (2g) × (H2
3/2 - H1
3/2)
(D) Q = (2/3) Cd × b × (2g) × (H2
2
- H1
2
)
Answer: Option C
Question No. 341
An error of 1% in measuring head over the apex of the notch (H) will produce an error of
_________ in discharge over a triangular notch.
(A) 1 %
(B) 1.5 %
(C) 2 %
(D) 2.5 %
Answer: Option D
Question No. 342
The Euler's equation for the motion of liquids is based upon the assumption that
(A) The fluid is non - viscous, homogeneous and incompressible
(B) The velocity of flow is uniform over the section
(C) The flow is continuous, steady and along the stream line
(D) All of the above
Answer: Option D
Question No. 343
The ratio of the inertia force to the viscous force is called
(A) Reynold's number
(B) Froude's number
(C) Weber's number
(D) Euler's number
Answer: Option A
Question No. 344
The total energy of a liquid particle in motion is equal to
(A) Pressure energy + kinetic energy + potential energy
(B) Pressure energy - (kinetic energy + potential energy)
(C) Potential energy - (pressure energy + kinetic energy
(D) Kinetic energy - (pressure energy + potential energy)
Answer: Option A
Question No. 345
Which of the following instrument can be used for measuring speed of a submarine moving in
deep sea?
(A) Venturimeter
(B) Orifice plate
(C) Hot wire anemometer
(D) Pitot tube
Answer: Option D
Question No. 346
The force present in a moving liquid is
(A) Inertia force
(B) Viscous force
(C) Gravity force
(D) All of these
Answer: Option D
Question No. 347
A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity
should a 1:25 model be towed through water?
(A) 10 m/sec
(B) 25 m/sec
(C) 2 m/sec
(D) 50 m/sec
Answer: Option C
Question No. 348
The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.
(A) Higher
(B) Lower
(C) Same
(D) None of these
Answer: Option B
Question No. 349
The flow in which the velocity vector is identical in magnitude and direction at every point, for any
given instant, is known as
(A) One dimensional flow
(B) Uniform flow
(C) Steady flow
(D) Turbulent flow
Answer: Option B
Question No. 350
The coefficient of discharge for an external mouthpiece depends upon
(A) Velocity of liquid
(B) Pressure of liquid
(C) Area of mouthpiece
(D) Length of mouthpiece
Answer: Option D
Question No. 351
The specific weight of water is 1000 kg/m3
(A) At normal pressure of 760 mm
(B) At 4°C temperature
(C) At mean sea level
(D) All the above
Answer: Option D
Question No. 352
If the depth of water in an open channel is greater than the critical depth, the flow is called
(A) Critical flow
(B) Turbulent flow
(C) Tranquil flow
(D) Torrential flow
Answer: Option C
Question No. 353
When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid
surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all
sides. This type of flow is known as
(A) Steady flow
(B) Turbulent flow
(C) Vortex flow
(D) Uniform flow
Answer: Option C
Question No. 354
The body will sink down if the force of buoyancy is __________ the weight of the liquid displaced.
(A) Equal to
(B) Less than
(C) More than
(D) None of these
Answer: Option B
Question No. 355
The total pressure on the surface of a vertical sluice gate 2 m x 1 m with its top 2 m surface being
0.5 m below the water level will be
(A) 500 kg
(B) 1000 kg
(C) 1500 kg
(D) 2000 kg
Answer: Option D
Question No. 356
The velocity at which the laminar flow stops, is known as
(A) Velocity of approach
(B) Lower critical velocity
(C) Higher critical velocity
(D) None of these
Answer: Option B
Question No. 357
The line of action of the buoyant force acts through the
(A) Centroid of the volume of fluid vertically above the body
(B) Centre of the volume of floating body
(C) Center of gravity of any submerged body
(D) Centroid of the displaced volume of fluid
Answer: Option D
Question No. 358
The buoyancy depends upon the
(A) Weight of the liquid displaced
(B) Pressure with which the liquid is displaced
(C) Viscosity of the liquid
(D) Compressibility of the liquid
Answer: Option A
Question No. 359
A glass tube of small diameter (d) is dipped in fluid. The height of rise or fall in the tube given by (where w = Specific weight of liquid, α = Angle of contact of the liquid surface, and σ = Surface tension)
A. 4wd/σ cosα
B. σ cosα/4wd
C. 4σ cosα/wd
D. wd/4σ cosα
Answer: Option C
Question No. 360
Two dimensional flows occurs when
(A) The direction and magnitude of the velocity at all points are identical
(B) The velocity of successive fluid particles, at any point, is the same at successive periods of
time
(C) The magnitude and direction of the velocity do not change from point to point in the fluid
(D) The fluid particles move in plane or parallel planes and the streamline patterns are identical
in each plane
Answer: Option D
Question No. 361
Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is
subjected to some pressure. The component of this pressure, in the direction of flow of the liquid,
is known as
(A) Lift
(B) Drag
(C) Stagnation pressure
(D) Bulk modulus
Answer: Option B
Question No. 362
Which of the following is dimensionless?
(A) Specific weight
(B) Specific volume
(C) Specific speed
(D) Specific gravity
Answer: Option D
Question No. 363
Coefficient of resistance is the ratio of
(A) Actual velocity of jet at vena-contracta to the theoretical velocity
(B) Area of jet at vena-contracta to the area of orifice
(C) Loss of head in the orifice to the head of water available at the exit of the orifice
(D) Actual discharge through an orifice to the theoretical discharge
Answer: Option C
Question No. 364
Mercury does not wet glass. This is due to property of liquid known as
(A) Adhesion
(B) Cohesion
(C) Surface tension
(D) Viscosity
Answer: Option C
Question No. 365
A flow in which __________ force is dominating over the viscosity is called turbulent flow.
(A) Elastic
(B) Surface tension
(C) Viscous
(D) Inertia
Answer: Option D
Question No. 366
Specific weight of sea water is more that of pure water because it contains
(A) Dissolved air
(B) Dissolved salt
(C) Suspended matter
(D) All of the above
Answer: Option D
Question No. 367
In an internal mouthpiece, the absolute pressure head at vena contracta is __________ the
atmospheric pressure head by an amount equal to height of the liquid above the vena contracta.
(A) Less than
(B) More than
(C) Equal to
(D) None of these
Answer: Option A
Question No. 368
An odd shaped body weighing 7.5 kg and occupying 0.01 m3
volume will be completely submerged
in a fluid having specific gravity of
(A) 1
(B) 1.2
(C) 0.8
(D) 0.75
Answer: Option D
Question No. 269
The factional resistance of a pipe varies approximately with __________ of the liquid.
(A) Pressure
(B) Velocity
(C) Square of velocity
(D) Cube of velocity
Answer: Option C
Question No. 370
For measuring flow by a Venturimeter, if should be installed in
(A) Vertical line
(B) Horizontal line
(C) Inclined line with flow downward
(D) In any direction and in any location
Answer: Option D
Question No. 371
The ratio of the inertia force to the elastic force is called
(A) Reynold's number
(B) Froude's number
(C) Weber's number
(D) Mach number
Answer: Option D
Question No. 372
All the terms of energy in Bernoulli's equation have dimension of
(A) Energy
(B) Work
(C) Mass
(D) Length
Answer: Option D
Question No. 373
The pressure at a point 4 m below the free surface of water is
(A) 19.24 kPa
(B) 29.24 kPa
(C) 39.24 kPa
(D) 49.24 kPa
Answer: Option C
Question No. 374
Specific weight of water in S.I. units is equal to
(A) 1000 N/m3
(B) 10000 N/m3
(C) 9.81 × 10³ N/m3
(D) 9.81 × 10⁶ N/m3
Answer: Option C
Question No. 375
The length AB of a pipe ABC in which the liquid is flowing has diameter (d1) and is suddenly
enlarged to diameter (d2) at B which is constant for the length BC. The loss of head due to sudden
enlargement is
(A) - (B) - (C) - (D) - Answer: Option C
Question No. 376
In an external mouthpiece, the absolute pressure head at vena contracta is __________ the
atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the
vena contracta.
(A) Less than
(B) More than
(C) Equal to
(D) None of these
Answer: Option A
Question No. 377
Poise is the unit of
(A) Surface tension
(B) Capillarity
(C) Viscosity
(D) Shear stress in fluids
Answer: Option C
Question No. 378
Viscous force is the __________ of shear stress due to viscosity and cross-section area of flow.
(A) Sum
(B) Different
(C) Product
(D) Ratio
Answer: Option C
Question No. 379
The siphon will work satisfactorily, if the minimum pressure in the pipe is __________ vapour
pressure of liquid.
(A) Equal to
(B) Less than
(C) More than
(D) None of these
Answer: Option C
Question No. 380
The tangential velocity of the water element having a free vortex is
(A) Directly proportional to its distance from the centre
(B) Inversely proportional to its distance from the centre
(C) Directly proportional to its (distance)2
from the centre
(D) Inversely proportional to its (distance)2
from the centre
Answer: Option B
Question No. 381
The horizontal component of buoyant force is
(A) Negligible
(B) Same as buoyant force
(C) Zero
(D) None of the above
Answer: Option C
Question No. 382
A flow in which the quantity of liquid flowing per second is constant, is called __________ flow.
(A) Steady
(B) Streamline
(C) Turbulent
(D) Unsteady
Answer: Option A
Question No. 383
The divergent portion of a Venturimeter is made longer than convergent portion in order to
(A) Avoid the tendency of breaking away the stream of liquid
(B) To minimise frictional losses
(C) Both (A) and (B)
(D) None of these
Answer: Option C
Question No. 384
According to Chezy's formula, the discharge through an open channel is (where A = Area of
flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)
(A) A × m × i)
(B) C × m × i)
(C) AC × m × i)
(D) mi × A × C)
Answer: Option C
Question No. 385
In a free vortex motion, the radial component of velocity everywhere is
(A) Maximum
(B) Minimum
(C) Zero
(D) Nonzero and finite
Answer: Option C
Question No. 386
Coefficient of contraction is the ratio of
(A) Actual velocity of jet at vena contracta to the theoretical velocity
(B) Loss of head in the orifice to the head of water available at the exit of the orifice
(C) Loss of head in the orifice to the head of water available at the exit of the orifice
(D) Area of jet at vena-contracta to the area of orifice
Answer: Option D
Question No. 387
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
Answer: Option D
Question No. 388
The flow in a pipe is turbulent when Reynold number is
(A) Less than 2000
(B) Between 2000 and 2800
(C) More than 2800
(D) None of these
Answer: Option C
Question No. 389
When the flow parameters at any given instant remain same at every point, then flow is said to be
(A) Quasi-static
(B) Steady state
(C) Laminar
(D) Uniform
Answer: Option D
Question No. 390
The total pressure on an immersed surface inclined at an angle θ with the liquid surface is
A. wA
B. wx
C. wAx
D. wAx/sinθ
Answer: Option C
Question No. 391
Rain drops are spherical because of
(A) Viscosity
(B) Air resistance
(C) Surface tension forces
(D) Atmospheric pressure
Answer: Option C
Question No. 392
The discharge over the trapezoidal notch is equal to the discharge over the rectangular notch
__________ the discharge over the triangular notch.
(A) Plus
(B) Minus
(C) Divide
(D) None of these
Answer: Option A
Question No. 393
Ratio of inertia force to surface Jension is known as
(A) Mach number
(B) Froude number
(C)
(D) Weber's number
Answer: Option D
Question No. 394
The sheet of water flowing over a notch or a weir is known as
(A) Sill or crest
(B) Nappe or vein
(C) Orifice
(D) None of these
Answer: Option B
Question No. 395
A structure used to dam up a stream or river over which the water flows is called
(A) Orifice
(B) Notch
(C) Weir
(D) Dam
Answer: Option C
Question No. 396
A body floating in a liquid is said to be in neutral equilibrium, if its metacentre
(A) Coincides with its centre of gravity
(B) Lies above its centre of gravity
(C) Lies below its centre of gravity
(D) Lies between the centre of buoyancy and centre of gravity
Answer: Option A
Question No. 397
General energy equation holds for
(A) Steady flow
(B) Turbulent flow
(C) Laminar flow
(D) Non-uniform flow
Answer: Option D
Question No. 398
The buoyancy depends on
(A) Mass of liquid displaced
(B) Viscosity of the liquid
(C) Pressure of the liquid displaced
(D) Depth of immersion
Answer: Option A
Question No. 399
The centre of gravity of the volume of the liquid displaced is called
(A) Centre of pressure
(B) Centre of buoyancy
(C) Metacentre
(D) None of these
Answer: Option B
Question No. 400
The Reynold's number of a ship is __________ to its velocity and length.
(A) Directly proportional
(B) Inversely proportional
(C) Square root of velocity
(D) None of these
Answer: Option A
Macking Floor plan in AutoCAD, Estimate & Costing, Repairing House, home loan sanction, interior design, AutoCAD Plan sanction, Site Supervisor, Civil Engineer, Architect, Developer, in Newtown, NKDA, HIDCO Call me 9804076776
No comments:
Post a Comment
If you are getting more information from civilengineerfriend page please give your comments. Share the page information in your whatsapp group. Subscribe our page to get more information.