650 Important Hydraulics And Fluid Mechanics MCQ Question and Answer | PDF Free Download
1.The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.
- AHigher
- BLower
- CSame
- DNone of these
2.The most economical section of a trapezoidal channel is one which has hydraulic mean depth equal to
- A1/2 × depth
- B1/2 × breadth
- C1/2 × sloping side
- D1/4 × (depth + breadth)
3.Pressure of the order of 10" torr can be measured by
- ABourdon tube
- BPirani Gauge
- CMicro-manometer
- DIonisation gauge
4.The rise of liquid along the walls of a revolving cylinder about the initial level is _________ the depression of the liquid at the axis of rotation.
- ASame as
- BLess than
- CMore than
- DNone of these
5.Newton's law of viscosity is a relationship between
- APressure, velocity and temperature
- BShear stress and rate of shear strain
- CShear stress and velocity
- DRate of shear strain and temperature
6.An open vessel of water is accelerated up an inclined plane. The free water surface will
- ABe horizontal
- BMake an angle in direction of inclination of inclined plane
- CMake an angle in opposite direction to inclination of inclined plane
- DAny one of above is possible
7.Alcohol is used in manometer because
- AIt has low vapour pressure
- BIt is clearly visible
- CIt has low surface tension
- DIt can provide longer column due to low density
8.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
- A14π R1/2/15Cd × a √(2g)
- B14π R3/2/15Cd × a √(2g)
- C14π R5/2/15Cd × a √(2g)
- D14π R7/2/15Cd × a √(2g)
9.Choose the wrong statement. Alcohol is used in manometer, because
- AIts vapour pressure is low
- BIt provides suitable meniscus for the inclined tube
- CIts density is less
- DIt provides longer length for a given pressure difference
10.The maximum value of the vane exit angle for centrifugal pump impeller is
- A10° to 15°
- B15° to 20°
- C20° to 25°
- D25° to 30°
11.According to fan laws, at constant weight of air or gas, the speed, capacity and pressure vary
- ADirectly as the air or gas density
- BInversely as square root of density
- CInversely as density
- DAs square of density
12.The runaway speed of a hydraulic turbine is the speed
- AAt full load
- BAt which there will be no damage to the runner
- CCorresponding to maximum overload permissible
- DAt which the turbine will run freely without load
13.The specific speed of a hydraulic turbine depends upon
- ASpeed and power developed
- BDischarge and power developed
- CSpeed and head of water
- DSpeed, power developed and head of water
14.For a floating body to be in equilibrium
- AMeta centre should be above equilibrium
- BCentre of buoyancy and equilibrium must lie on same vertical plane
- CA righting couple should be formed
- DAll of the above
15.A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if
- ALength of both the pipes is same
- BDiameter of both the pipes is same
- CLoss of head and discharge of both the pipes is same
- DLoss of head and velocity of flow in both the pipes is same
16.Mercury is often used in barometer because
- AIt is the best liquid
- BThe height of barometer will be less
- CIts vapour pressure is so low that it may be neglected
- DBoth (B) and (C)
17.The specific speed of a centrifugal pump, delivering 750 liters of water per second against a head of 15 meters at 725 r.p.m., is
- A24.8 r.p.m.
- B48.2 r.p.m
- C82.4 r.p.m.
- D248 r.p.m
18.The discharge through a reaction turbine with increase in unit speed
- AIncreases
- BDecreases
- CRemain unaffected
- DFirst increases and then decreases
19.If the ratio's of the corresponding forces acting at corresponding points are equal, then the model and the prototype are said to have.
- AGeometric similarity
- BKinematic similarity
- CDynamic similarity
- DNone of these
20.At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be
- AMinimum
- BMaximum
- CZero
- DCould be any value