Fluid Mechanics Mcqs for Chemical - Set 17

1)   The maximum head that can be developed by a single impeller is _____________ ft?

a. 25
b. 100
c. 250-300
d. 1000
Answer  Explanation 

ANSWER: 250-300

Explanation:
No explanation is available for this question!


2)   Location of vena-contracta in an orificemeter does not depend upon the________________?

a. Type of orifice
b. Density, viscosity & compressibility of the fluid
c. Ratio of pipe diameter to orifice diameter
d. Pipe roughness
Answer  Explanation 

ANSWER: Type of orifice

Explanation:
No explanation is available for this question!


3)   Path followed by water jet issuing from the bottom of a water tank will be a__________________?

a. Parabola (vertex being at the opening)
b. Hyperbola
c. Horizontal straight line
d. Zig-zag path (which is geometrically undefined)
Answer  Explanation 

ANSWER: Parabola (vertex being at the opening)

Explanation:
No explanation is available for this question!


4)   For flow past a flat plate, if „x‟ is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to________________?

a. √x
b. 1/√x
c. x
d. 1/x
Answer  Explanation 

ANSWER: √x

Explanation:
No explanation is available for this question!


5)   The unit of bulk modulus of elasticity for a liquid in S.I. unit is____________________?

a. N
b. N/m
c. N/m2
d. N/m3
Answer  Explanation 

ANSWER: N/m2

Explanation:
No explanation is available for this question!


6)   It is possible to integrate an automatic flow controller to a________________?

a. Flow nozzle
b. Venturimeter
c. Rotameter
d. None of these
Answer  Explanation 

ANSWER: Rotameter

Explanation:
No explanation is available for this question!


7)   Friction factor for a hydraulically smooth pipe at NRe = 2100 is f1. If the pipe is further smoothened (i.e., roughness is reduced), the friction factor at the same value of NRe, will_______________?

a. Increase
b. Decrease
c. Remain unchanged
d. Increase or decrease depending on the pipe material
Answer  Explanation 

ANSWER: Increase

Explanation:
No explanation is available for this question!


8)   The dimension of surface tension is________________?

a. ML-2
b. MT-2
c. MLT-2
d. ML-2T
Answer  Explanation 

ANSWER: MT-2

Explanation:
No explanation is available for this question!


9)   N. second/m2 is___________________?

a. The S.I. unit of dynamic viscosity
b. The S.I. unit of kinematic viscosity
c. Equivalent to one poise
d. Equivalent to one stoke
Answer  Explanation 

ANSWER: The S.I. unit of dynamic viscosity

Explanation:
No explanation is available for this question!


10)   Water flow rate in a pipe of 3.5 metres diameter can be most economically and conveniently measured by a/an ________________?

a. Pitot tube
b. Venturimeter
c. Orificemeter
d. Rotameter
Answer  Explanation 

ANSWER: Pitot tube

Explanation:
No explanation is available for this question!


11)   Maintenance cost of a ______________ pump for a particular duty is the least?

a. Centrifugal
b. Reciprocating
c. Volute
d. Gear
Answer  Explanation 

ANSWER: Centrifugal

Explanation:
No explanation is available for this question!


12)   With a constant diameter impeller of a centrifugal pump _____________________?

a. Its capacity varies directly as the square of speed
b. Head varies as the square of speed
c. Horsepower input varies as the square of speed
d. Head varies as the speed
Answer  Explanation 

ANSWER: Head varies as the square of speed

Explanation:
No explanation is available for this question!


13)   Which of the following is an undesirable property of a manometric liquid ?

a. Non-sticky & non-corrosive nature
b. High vapour pressure
c. Low viscosity & surface tension
d. Low co-efficient of thermal expansion
Answer  Explanation 

ANSWER: High vapour pressure

Explanation:
No explanation is available for this question!


14)   In Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the ______________ of its diameter?

a. Inverse
b. Square root
c. Second power
d. First power
Answer  Explanation 

ANSWER: Square root

Explanation:
No explanation is available for this question!


15)   The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is_________________?

a. Q∝N : H∝N2 : P∝N3
b. Q∝N2 : H∝N3 : P∝N
c. Q∝N : H∝N3 : P∝N2
d. Q∝N3 : H∝N : P∝N2
Answer  Explanation 

ANSWER: Q∝N : H∝N2 : P∝N3

Explanation:
No explanation is available for this question!


16)   A bed consists of particles of density 2000 kg/m3. If the height of the bed is 1.5 metres and its porosity 0.6, the pressure drop required to fluidise the bed by air is_________________?

a. 25.61 kPa
b. 11.77 kPa
c. 14.86 kPa
d. 21.13 kPa
Answer  Explanation 

ANSWER: 11.77 kPa

Explanation:
No explanation is available for this question!


17)   Efficiency of power transmission (ε) through a circular pipe is given by (ht – hf)/ht, which has a maximum value of _____________ percent?

a. 33:3
b. 50
c. 66.6
d. 88.8
Answer  Explanation 

ANSWER: 66.6

Explanation:
No explanation is available for this question!


18)   For a reciprocating pump, the indicator diagram is the graph between the________________?

a. Discharge and overall efficiency
b. Volume swept by piston for one complete revolution and the pressure in the cylinder
c. Angle swept by the crank pin at any instant and the discharge
d. None of these
Answer  Explanation 

ANSWER: Volume swept by piston for one complete revolution and the pressure in the cylinder

Explanation:
No explanation is available for this question!


19)   Power requirement of fans having constant wheel diameter varies _____________ fan speed?

a. As square of
b. Directly as
c. As cube of
d. None of these
Answer  Explanation 

ANSWER: As cube of

Explanation:
No explanation is available for this question!


20)   Which is not a variable head meter _________________?

a. Venturimeter
b. Pitot tube
c. Rotameter
d. None of these
Answer  Explanation 

ANSWER: Rotameter

Explanation:
No explanation is available for this question!


21)   Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of ______________ pressure?

a. Small differential
b. Atmospheric
c. Absolute
d. Gage
Answer  Explanation 

ANSWER: Small differential

Explanation:
No explanation is available for this question!


22)   Creeping flow around a sphere is defined, when particle Reynolds number is___________________?

a. < 2100
b. < 0.1
c. > 2.5
d. < 500
Answer  Explanation 

ANSWER: < 0.1

Explanation:
No explanation is available for this question!


23)   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
Answer  Explanation 

ANSWER: Absolute roughness increases linearly with time

Explanation:
No explanation is available for this question!


24)   In fluid flow, the stagnation point is defined as a point, where the _____________ is zero?

a. Flow velocity
b. Pressure
c. Total energy
d. All A., B. and C.
Answer  Explanation 

ANSWER: Flow velocity

Explanation:
No explanation is available for this question!


25)   A hydraulic ram acts as a/an ______________ pump?

a. Centrifugal
b. Reciprocating
c. Impulse
d. Parallel cylinder
Answer  Explanation 

ANSWER: Impulse

Explanation:
No explanation is available for this question!


26)   Viscosity of water is about _____________ times that of air at room temperature?

a. 15
b. 55
c. 155
d. 1050
Answer  Explanation 

ANSWER: 55

Explanation:
No explanation is available for this question!


27)   Sewage sludge is an example of the ______________ fluid?

a. Bingham plastic
b. Newtonian
c. Pseudo plastic
d. Dilatent
Answer  Explanation 

ANSWER: Bingham plastic

Explanation:
No explanation is available for this question!


28)   The ratio of hydrodynamic boundary layer to thermal boundary layer thickness in case of liquid metals is__________________?

a. < 1
b. 1
c. > 1
d. 2
Answer  Explanation 

ANSWER: < 1

Explanation:
No explanation is available for this question!


29)   High specific speed of a pump implies that, it is a/an _____________ pump?

a. Centrifugal
b. Mixed flow
c. Axial flow
d. None of these
Answer  Explanation 

ANSWER: Axial flow

Explanation:
No explanation is available for this question!


30)   Velocity of liquid hydrocarbon fuels in a pipeline cannot be measured by magnetic flowmeters, because their ______________ is very low/small?

a. Thermal conductivity
b. Electrical conductivity
c. Specific gravity
d. Electrical resistivity
Answer  Explanation 

ANSWER: Electrical conductivity

Explanation:
No explanation is available for this question!


31)   The friction factor is___________________?

a. Always inversely proportional to the Reynolds number
b. Not dimensionless
c. Not dependent on the roughness of the pipe
d. None of these
Answer  Explanation 

ANSWER: None of these

Explanation:
No explanation is available for this question!


32)   What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition ?

a. 0.5
b. 0.67
c. 1
d. 2
Answer  Explanation 

ANSWER: 2

Explanation:
No explanation is available for this question!


33)   Turbine impeller____________________?

a. Produces only radial current
b. Produces only tangential current
c. Is effective over wide range of viscosities
d. Does not produce tangential current
Answer  Explanation 

ANSWER: Is effective over wide range of viscosities

Explanation:
No explanation is available for this question!


34)   One dimensional fluid flow implies the ________________________?

a. Flow in straight lines only
b. Uniform flow
c. Steady uniform flow
d. Flow in which transverse components are zero
Answer  Explanation 

ANSWER: Flow in which transverse components are zero

Explanation:
No explanation is available for this question!


35)   For laminar flow through a closed conduit____________________?

a. Vmax = 2Vav
b. Vmax = Vav
c. Vmax = 1.5Vav
d. Vmax = 0.5Vav
Answer  Explanation 

ANSWER: Vmax = 2Vav

Explanation:
No explanation is available for this question!


36)   Each term in Bernoulli‟s equation represents the _____________ of the fluid?

a. Energy per unit mass
b. Energy per unit weight
c. Force per unit mass
d. None of these
Answer  Explanation 

ANSWER: Energy per unit weight

Explanation:
No explanation is available for this question!


37)   For liquid flow through a packed bed, the superficial velocity as compared to average velocity through the channel in the bed is________________?

a. More
b. Less
c. Equal
d. Independent of porosity
Answer  Explanation 

ANSWER: Less

Explanation:
No explanation is available for this question!


38)   The equivalent diameter for pressure drop calculation for a fluid flowing through a rectangular cross-section channels having sides ‘x’ & ‘y’ is given by_________________?

a. 2xy/(x + y)
b. xy/(x + y)
c. (x + y)/2xy
d. (x + y)/xy
Answer  Explanation 

ANSWER: 2xy/(x + y)

Explanation:
No explanation is available for this question!


39)   The nominal size of a hose pipe is specified by its _________________?

a. I.D.
b. O.D.
c. Thickness
d. None of these
Answer  Explanation 

ANSWER: I.D.

Explanation:
No explanation is available for this question!


40)   An equipotential line is _____________ to the velocity vector at every point?

a. Normal
b. Parallel
c. Tangential
d. None of these
Answer  Explanation 

ANSWER: Normal

Explanation:
No explanation is available for this question!