Section 12 Flashcards
__________ is an example of axial flow impeller.
a. Paddle
b. Turbine
c. Propeller
d. all (a), (b) and(c)
c. Propeller
Froude number is not a factor
a. for Reynolds number greater than 300.
b. when there is no vortex formation.
c. for unbaffled tank.
d. none of these.
b. when there is no vortex formation.
If three pipes of different diameters, lengths & friction factors are connected in parallel, then (where, Q = flow rate, V= fluid velocity f = friction factor).
a. Q = Q1 + Q2 + Q3
b. V1 = V2 = V3
c. Q1 = Q2 = Q3
d. f = f1 + f2 + f3
a. Q = Q1 + Q2 + Q3
Horsepower requirement for given pump capacity depends upon the
a. specific gravity of the liquid
b. suction lift
c. discharge head
d. all (a), (b) and (c)
d. all (a), (b) and (c)
Bernoulli’s equation accounts for the
a. various momentums
b. various masses
c. different forms of mechanical energy
d. none of these
c. different forms of mechanical energy
__________ pumps are a group of vacuum pumps.
a. Hyter
b. Sump
c. Mono
d. Submerged
a. Hyter
Plunger pumps are used for
a. higher pressure
b. slurries
c. viscous mass
d. none of these
a. higher pressure
What is the ratio of displacement thickness to nominal thickness for a linear distribution of velocity in the boundary layer on a flat plate ?
a. 0.5
b. 1
c. 1.5
d. 2
a. 0.5
In turbulent flow, the
a. fluid particles move in an orderly manner.
b. momentum transfer is on molecular scale only.
c. shear stress is caused more effectively by cohesion than
momentum transfer.
d. shear stresses are generally larger than in a similar laminar flow.
d. shear stresses are generally larger than in a similar laminar flow.
Momentum correction factor used in fluid flow problems accounts for the
a. change in direction of flow.
b. change in total energy.
c. change in pressure.
d. non uniform direction of velocities at inlet & outlet sections.
d. non uniform direction of velocities at inlet & outlet sections.
Design of the casing of centrifugal pump should be such as to minimise the
a. back flow through impeller
b. loss of kinetic head
c. loss of static head
d. none of these
b. loss of kinetic head
Which of the following is used for pumping crude oil from oil well ?
a. Single stage centrifugal pump
b. Gear pump
c. Screw pump
d. Duplex/triplex reciprocating pump
d. Duplex/triplex reciprocating pump
The energy loss in flow through ven-turimeter is less than that through flow nozzle, because in case of a flow nozzle, the
a. length is shorter.
b. throat diameter is more.
c. sudden expansion of flow in the downstream occurs.
d. distance between the throat and the inlet is more.
c. sudden expansion of flow in the downstream occurs.
__________ flow means the flow of incompressible fluid with no shear.
a. Potential
b. Streamline
c. Creep
d. Boundary layer
a. Potential
The continuity equation
a. relates mass flow rate along a stream tube.
b. relates work and energy.
c. Stipulates that Newton’s second law of motion must be satisfied at every point in the fluid.
d. none of these.
a. relates mass flow rate along a stream tube.
The energy loss over a length of pipeline according to Darcy-Weisbach
equation for pipe flow is…..the mean velocity of flow.
a. directly proportional to
b. directly proportional to square of
c. inversely proportional to
d. inversely proportional to square of
b. directly proportional to square of
Pressure drop in a packed bed for laminar flow is given by the __________ equation.
a. Kozney-Karman
b. Blake-Plummer
c. Leva’s
d. Fanning friction factor
a. Kozney-Karman
The fluid velocity varies as the cube of the cylinderical pipe diameter in case of steady state laminar flow at constant pressure drop for __________ fluid.
a. Newtonion
b. pseudoplastic
c. dilatent
d. Bingham plastic
b. pseudoplastic
Stoke’s law is valid, when NRe, p is less than
a. 2
b. 100
c. 2100
d. 700
a. 2
Froude number is the ratio of
a. shear stress to gravitational stress.
b. drag stress to shear stress.
c. inertial stress to shear stress.
d. inertial stress to gravitational stress.
d. inertial stress to gravitational stress.
Normal depth in open channel flow is the depth of flow in the channel
a. corresponding to uniform flow.
b. measured normal to the channel bed.
c. corresponding to steady flow.
d. none of these.
a. corresponding to uniform flow.
Which of the following flow measuring devices is an area meter ?
a. Venturimeter
b. Orifice meter
c. Anemometer
d. Rotameter
d. Rotameter
With decrease in particle size to be fluidised by a particular fluid, the operating range of fluidisation velocity
a. widens
b. squeezes
c. does not change
d. unpredictable from the data
c. does not change
Diaphragm valves are used for handling __________ fluids.
a. corrosive
b. viscous
c. non-Newtonion
d. solid suspended
a. corrosive
The schedule number of a pipe is an indication of its
a. size
b. roughness
c. material density
d. wall thickness
Minimum porosity for fluidisation is
a. that corresponding to static bed.
B; that corresponding to completely fluidised bed.
c. the porosity of the bed when true flluidisation begins.
d. less than that of the’ static bed.
c. the porosity of the bed when true flluidisation begins.
A centrifugal pump used to pump water is used to pump an oil with specific gravity of 0.8 at the same rate. The power consumption will now
a. increase
b. decrease
c. remain same
d. data insufficient to predict
b. decrease
Steady non-uniform flow is exemplified by flow through a/an
a. long pipe at constant rate.
b. long pipe at decreasing rate.
c. expanding tube at increasing rate.
d. expanding tube at constant rate.
d. expanding tube at constant rate.
The maximum depth from which a centrifugal pump can draw water is
a. dependent on the speed of the pump.
b. dependent on the power of the pump.
c. 34 feet.
d. 150 feet.
c. 34 feet.
Hot wire anemometer is used to measure the
a. velocity of liquids.
b. temperature of liquids.
c. velocity of gases.
d. pressure of liquids.
c. velocity of gases.
Propeller type centrifugal pumps are most suitable for
a. high capacity at high heads.
b. high capacity at low heads.
c. low capacity at high heads.
d. low capacity at low heads.
b. high capacity at low heads.
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. Newtonion
b. dilatant
c. pseudoplastic
d. non-Newtonion
a. Newtonion
Momentum transfer in laminar flow of fluids results due to the
a. viscosity
b. density
c. velocity gradient
d. none of these
c. velocity gradient
The capillary rise of mercury is maximum in glass tube of dia __________
mm.
a. 0.5
b. 1
c. 2
d. 5
a. 0.5
Diaphragm pumps are used to transport
a. solids
b. liquids
c. fluids
d. slurries
d. slurries
For steady ideal fluid flow, the Bernoulli’s equation states that the
a. velocity is constant along a stream line.
b. energy is constant throughout the fluid
c. energy is constant along a stream line, but may vary across stream lines
d. none of these
c. energy is constant along a stream line, but may vary across stream lines
In case of a centrifugal pump, the theoretical head developed is dependent on the __________ the impeller.
a. speed of
b. diameter of
c. fluid velocity leaving
d. all (a), (b) and (c)
d. all (a), (b) and (c)
A hydraulic press has a ram of 10 cms in diameter and a plunger of 1 cm in
diameter. The force required on the plunger to raise a weight of 10 tons on the
ram is __________ kg.
a. 10
b. 100
c. 1000
d. 10000
b. 100
Choose the set of pressure intensities that are equivalent.
a. 4.33 psi, 10 ft. of water, 8.83 inches of Hg.
b. 4.33 psi, 10 ft. of water, 20.7 inches of Hg.
c. 10 psi, 19.7 ft. of water, 23.3 inches of Hg.
d. 10 psi, 19.7 ft. of water, 5.3 inches of Hg.
a. 4.33 psi, 10 ft. of water, 8.83 inches of Hg.
Pick out the wrong statement about a streamline.
a. It is always parallel to the main direction of the fluid flow.
b. It is a line across which there is no flow and it is equivalent to a rigid boundary.
c. Streamlines intersect at isolated point of zero velocity and
infinite velocity.
d. The fluid lying between any two streamlines can be considered to be in isolation and the streamline spacing varies inversely as the velocity.
a. It is always parallel to the main direction of the fluid flow.
The most serious disadvantage of an orificemeter is that
a. it is not very accurate.
b. it is very costly.
c. most of the pressure drop is not recoverable.
d. it is not suitable for measuring gas flow.
c. most of the pressure drop is not recoverable.
The discharge through a rectangular weir varies as
a. H^1/2
b. H^5/2
c. H^2/5
d. H^3/2
d. H^3/2
In case of supersonic flow of a fluid through pipeline, the ‘Mach number’ is
a. 0
b. 1
c. < 1
d. > 1
d. > 1
- A centrifugal pump has the following specifications:
Power = 4 H.P.; Speed = 800 rpm
Head = 8 metres Flow = 1000 litres/minutes.
If its speed is halved, the power consumed now will be __________ hp.
a. 0.5
b. 2
c. 4
d. 1
a. 0.5
Transition length for turbulent flow in smooth pipe is equal to __________ times the pipe diameter.
a. 0.5
b. 5
c. 50
d. 100
c. 50
Disc compensators are provided in large diameter fuel gas carrying pipelines to
a. keep the pipe in proper orientation.
b. make the pipe joint leak-proof.
c. account for contraction/expansion of pipe due to temperature changes of the surroundings.
d. account for the pressure variation side the pipeline.
c. account for contraction/expansion of pipe due to temperature changes of the surroundings.
Discharge from a 24 inch pipe of water at 10 ft/sec will be __________ ft3/sec.
a. 7.65
b. 32.36
c. 48.22
d. 125.6
d. 125.6
Paper pulp is an example of __________ fluid.
a. dilatant
b. bingham plastic
c. Newtonion
d. pseudoplastic
b. bingham plastic
