Section 4 Flashcards
Pascal law is not applicable for a/an __________ fluid.
A. accelerating frictionless
B. static
C. uniformly moving
D. none of these
D. none of these
In a fluidised bed reactor
A. temperature gradients are very high.
B. temperature is more or less uniform.
C. hot spots are formed.
D. segregation of the solids occurs.
B. temperature is more or less uniform.
The flow of a liquid through tapering pipe at a constant rate is an example of __________ flow.
A. steady uniform
B. steady non uniform
C. unsteady uniform
D. unsteady non uniform
B. steady non uniform
Pick out the correct statement pertaining to transition/ entrance length in fluid flow.
A. The length of entrance region of pipe, in which full development of fluid flow takes place such that velocity profile does not change downstream, is called the transition length.
B. Transition length for laminar flow of Newtonion fluids in a pipe of diameter ‘d’ is equal to 0.05. D.NRe.
C. Transition length for turbulent flow of Newtonion fluids in a smooth pipe of diameter ‘d’ is equal to 50 D.
D. all (a), (b) and (c).
D. all (a), (b) and (c).
A perfect gas
A. does not satisfy PV= nRT.
B. is incompressible and has zero viscosity.
C. has constant specific heat.
D. can’t develop shear stresses.
C. has constant specific heat.
In a/an __________ , the flow rate of fluids is obtained by measuring the difference between the impact and the static pressure.
A. rotameter
B. pitot tube
C. venturimeter
D. flow nozzle
B. pitot tube
Speed of sound in an ideal gas depends on its
A. temperature
B. pressure
C. specific volume
D. none of these
A. temperature
A centrifugal pump designed for handling water (μ = 1 cp) will deliver __________ when pumping a thicker oil (μ = 30 cp).
A. less head & capacity
B. more head
C. more capacity
D. less head & more capacity
A. less head & capacity
If ‘x’ is the depth of flow in an open channel of large width, then the hydraulic radius is equal to
A. x
B. x/2
C. x/3
D. 2x/3
A. x
In fluid flow, the boundary layer separation can not occur
A. in case of boundaries experiencing form drag.
B. at points of abrupt changes in the flow directions.
C. in laminar flow.
D. none of these.
D. none of these.
For a given fluid flow rate, which of the following incurs maximum head loss ?
A. Orifice meter
B. Venturimeter
C. Flow nozzle
D. All of them incur the same head loss
A. Orifice meter
Which of the following assumptions enables the Euler’s equation of motion to be integrated ?
A. The fluid is incompressible.
B. The fluid is non-viscous.
C. The continuity equation is satisfied.
D. The flow is rotational and incompressible.
A. The fluid is incompressible.
- A fluid whose apparent viscosity increases with shear rate is termed as the __________ fluid.
A. Newtonion
B. viscous
C. dilatant
D. non-viscous
C. dilatant
Which of the following is the most common pump for pumping either raw sewage or sludge ?
A. Electromagnetic pump
B. Centrifugal pump
C. Reciprocating pump
D. Gear pump
C. Reciprocating pump
Transition length for a turbulent fluid entering into a pipe is around __________ times the pipe diameter.
A. 5
B. 50
C. 500
D. 1000
B. 50
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
C. < 1
Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have
A. very low speeds.
B. smaller discharge.
C. higher capital &maintenance cost.
D. high vibrations.
C. higher capital &maintenance cost.
Which is the correct relationship for a centrifugal pump ? (where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm)
A. D = 1840 H0.5/N
B. D = 1840 N/H0.5
C. H = 1840 D0.5/N
D. D = 1840 H/N
A. D = 1840 H0.5/N
Which of the following pipe bends will incur the largest head loss ?
A. U-bend
B. 30° bend
C. 45° bend
D. 90° bend
A. U-bend
Which is the most efficient and best for measuring very small flow rate of gases ?
A. Venturimeter
B. Orifice meter
C. Rotameter
D. Flow nozzle
When the water is warm, the height to which it can be lifted by a pump
A. decreases due to reduced viscosity.
B. decreases due to reduced vapour pressure.
C. increases due to increased vapour pressure
D. decreases due to increased frictional resistance.
B. decreases due to reduced vapour pressure.
Viscosity of water at 40°C lies in the range of
A. 1 x 10^-3 to 2x10^-3kg/m.s
B. 0.5 x 10^-3 to 1 x 10^-3 kg/m.s
C. 1 to 2 kg/m.s
D. 0.5 to 1 kg/m.s
B. 0.5 x 10^-3 to 1 x 10^-3 kg/m.s
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 new discharge will be __________ litres/minute.
A. 500
B. 200
C. 1000
D. 750
A. 500
The dimension of kinematic viscosity is
A. ML^-2 T^-1
B. L^2 T^-1
C. ML^-2T^-2
D. none of these
B. L^2 T^-1
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. 52 m/sec
D. 5 m/sec
B. 10 m/sec
Turbulent flow generally occurs for cases involving
A. highly viscous fluid
B. very narrow passages
C. very slow motion
D. none of these
D. none of these
Lower BWG means __________ of the tube.
A. lower thickness
B. lower cross-section
C. outer diameter
D. inner diameter
B. lower cross-section
For laminar flow of Newtonion fluid in a circular pipe, the velocity distribution is a function of the distance ‘d’ measured from the centre line of the pipe, and it follows a __________ relationship.
A. logarithmic
B. parabolic
C. hyperbolic
D. linear
B. parabolic
The Prandtl mixing length is
A. zero at the pipe wall and is a universal constant.
B. independent of radial distance from the pipe axis.
C. independent of the shear stress.
D. useful for computing laminar flow problems.
D. useful for computing laminar flow problems.
As the velocity V and thus the Reynolds number of a flow past a sphere increases from very low value, the drag force for Re «_space;1
A. increases linearly with V .
B. decreases linearly with V.
C. decreases as V2.
D. none of these.
A. increases linearly with V .
Self-priming centrifugal pump can be used for
A. booster service.
B. pumping liquid fertilisers (e.g. liquid NH3).
C. pumping industrial wastes.
D. all (a), (b) and (c).
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)
D. all (a), (b) and (c)
Bernoull’s equation does not apply to the functioning of a/an
A. venturimeter
B. orificem
C. pitot tube
D. none of these
D. none of these
Pascal’s law is valid, only when the fluid is
A. frictionless and at rest.
B. at rest.
C. at rest and when the frictionless fluid is in motion.
D. none of these.
B. at rest.
The pressure head of a flow meter remains constant for
A. venturimeter
B. orificemeter
C. rotameter
D. pitot tube
C. rotameter
A venturimeter can not be used for the direct measurement of
A. datum difference in the stretch of pipeflow
B. pressure difference in the flow throughpipeline.
C. friction loss in pipe flow.
D. all (a), (b) and (c).
D. all (a), (b) and (c).
A double acting reciprocating pump compared to a single acting pump (of almost same size working under same pressure levels) would give almost double
A. head
B. discharge
C. efficiency
D. none of these
B. discharge
Which of the following is used for very accurate measurement of flow of gas at low velocity ?
A. Pitot tube
B. Rotameter
C. Segmental orificemeter
D. Hot wire anemometer
D. Hot wire anemometer
In Newton’s law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is
A. 0.44
B. 0.044
C. 4.4
D. 44
A. 0.44
A pressure of 10 m head of water is equivalent to __________ kN/m2.
A. 98
B. 147
C. 196
D. 49
A. 98
A pressure head of 320 metres of water in meters of CCl4 (sp.gr = 1.6) will be
A. 100
B. 200
C. 320
D. 160
B. 200
