In the Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is ______________ the fluid viscosity?

Inversely proportional to the square root of

In the complete turbulence zone (in rough pipes), the____________________?

Rough and smooth pipes have the same friction factor

Laminar film covers the roughness projections

Friction factor depends upon NRe only

Friction factor is independent of the relative roughness

In parallel pipe problems, the__________________?

Discharge is the same through all the pipes

Head loss is the same through each pipe

Discharge is the same through all the pipes

Total head loss is equal to the sum of the head losses through each pipe

In magnetic flow meters, voltage generation is________________?

Due to the motion of conducting fluid through an externally generated uniform field

Proportional to the fluid velocity

In isotropic turbulence, the _____________ are equal to each other?

Root mean square of velocity fluctuations in the three co-ordinate directions

Mean square of velocity fluctuations in the three co-ordinate directions

Root mean square of velocity fluctuations in the three co-ordinate directions

In hindered settling, the particles are_________________________?

Not affected by other particles and the wall

In frictional fluid flow, the quantity, (P/ρ) + (V2/2gc) + gz/gc) is___________________?

Increased in the direction of flow

Not constant along a streamline

Increased in the direction of flow

In fluid flow, the boundary layer separation cannot occur___________________?

In case of boundaries experiencing form drag

At points of abrupt changes in the flow directions

In fluid flow, cavitation is caused, if the____________________?

Fluid velocity decreases to zero

Flow pressure approaches its vapor pressure at the prevailing temperature

In deriving Bernoulli’s equation, fluid is assumed to be________________?

Uniform, steady, incompressible, along a streamline

Incompressible, frictionless, steady, along a streamline

Uniform, steady, incompressible, along a streamline

Steady, density being pressure dependent, frictionless

In continuous fluidisation_________________?

The pressure drop is less than that for batch fluidisation

Solids are completely entrained

The pressure drop is less than that for batch fluidisation

There is no entrainment of solids

Velocity of the fluid is very small

In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes_______________?

More than liquid vapor pressure

Less than liquid vapor pressure

In case of turbulent flow of fluid through a circular pipe, the __________________?

Mean flow velocity is about 0.5 times the maximum velocity

Velocity profile becomes flatter and flatter with increasing Reynolds number

Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius)

Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more

In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow ?

Water discharge from a vertical vessel in which constant level is maintained

Discharge of water by a centrifugal pump being run at a constant rpm

Water flow in the suction and discharge pipe of a reciprocating pump

Water discharge from a vertical vessel in which constant level is maintained

Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe

In case of laminar flow of fluid through a circular pipe, the__________________?

Velocity profile varies hyperbolically and the shear stress remains constant over the crosssection

Shear stress over the cross-section is proportional to the distance from the surface of the pipe

Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder

Velocity profile varies hyperbolically and the shear stress remains constant over the crosssection

Average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)

In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of___________________?

Friction co-efficient for flows at equal Reynold number

In case of end to end connection of two or more pipes in series, the ______________ each pipe?

Same rate of flow passes through

Rate of flow in each pipe is proportional to the length of

Total flow rate is the sum of flow rate in

In case of Couette flow, the fluid flow is between two large flat parallel plates with___________________?

Bottom plate moving and the top plate fixed

Top plate moving and the bottom plate fixed

Bottom plate moving and the top plate fixed

In case of a pipe exit fitted with a nozzle, the____________________?

Conversion of kinetic head to pressure head is facilitated

Conversion of pressure head to kinetic head is facilitated

Power transmitted through the nozzle is maximum, when the head lost due to friction in the pipe is equal to one third of the total supply head

In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is___________________?

Dependent on its cross-sectional area

In area meter (e.g., Rotameter), with increase in the fluid flow rate, the___________________?

Area through which fluid flows does not vary

Pressure drop increases linearly

Pressure drop is almost constant

Area through which fluid flows does not vary

In an incompressible fluid, the density is____________________?

Sensible to changes in both temperature & pressure

Greatly affected by moderate changes in pressure

Greatly affected only by moderate changes in temperature

Not affected with moderate change in temperature & pressure

Sensible to changes in both temperature & pressure

In an incompressible flow of fluid, the fluid ________________?

Compressibility is greater than zero

Density does not change with pressure & temperature

In a free vortex, the_____________________?

Velocity changes linearly with radial distance

Radial component of velocity is same everywhere

In a fluidised bed reactor___________________?

Temperature gradients are very high

Temperature is more or less uniform

Segregation of the solids occurs

659 + Mcqs in Fluid Mechanics for Chemical in Chemical Engineering Page 8 McqOptions

351.	In the Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is ______________ the fluid viscosity?
A.	Directly proportional to
B.	Inversely proportional to
C.	Inversely proportional to the square root of
D.	Independent of
Answer» C. Inversely proportional to the square root of

Discussion

352.	In the low Reynolds number region, the drag force on a sphere is proportional to_______________?
A.	V
B.	V2
C.	V4
D.	V0.5
Answer» B. V2

Discussion

353.	In the laminar boundary layer flow over a flat plate, the ratio (δ/x) varies as: (where, ‘δ’ is the boundary layer thickness and ‘x’ is the distance from the leading edge in the direction of flow)?
A.	Re
B.	√Re
C.	1/Re
D.	Re-1/2
Answer» E.

Discussion

354.	In the complete turbulence zone (in rough pipes), the____________________?
A.	Rough and smooth pipes have the same friction factor
B.	Laminar film covers the roughness projections
C.	Friction factor depends upon NRe only
D.	Friction factor is independent of the relative roughness
Answer» E.

Discussion

355.	In power law, δ = [A (du/dy)2 + B] then the fluid is__________________?
A.	Newtonian
B.	Dilatant
C.	Thixotropic
D.	Rheopectic
Answer» B. Dilatant

Discussion

356.	In parallel pipe problems, the__________________?
A.	Head loss is the same through each pipe
B.	Discharge is the same through all the pipes
C.	Total head loss is equal to the sum of the head losses through each pipe
D.	None of these
Answer» B. Discharge is the same through all the pipes

Discussion

357.	In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is_________________?
A.	0.5
B.	0.84
C.	1.84
D.	1.25
Answer» D. 1.25

Discussion

358.	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» C. Second power

Discussion

359.	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
Answer» B. 0.044

Discussion

360.	In magnetic flow meters, voltage generation is________________?
A.	Due to the motion of conducting fluid through an externally generated uniform field
B.	Proportional to the fluid velocity
C.	Both A. and B.
D.	Neither A. nor B.
Answer» D. Neither A. nor B.

Discussion

361.	In laminar flow through a round tube, the discharge varies ______________________?
A.	Linearly as the viscosity
B.	Inversely as the pressure drop
C.	Inversely as the viscosity
D.	As the square of the radius
Answer» D. As the square of the radius

Discussion

362.	In isotropic turbulence, the _____________ are equal to each other?
A.	Temporal velocity components
B.	Mean square of velocity fluctuations in the three co-ordinate directions
C.	Root mean square of velocity fluctuations in the three co-ordinate directions
D.	None of these
Answer» C. Root mean square of velocity fluctuations in the three co-ordinate directions

Discussion

363.	In hindered settling, the particles are_________________________?
A.	Placed farther from the wall
B.	Not affected by other particles and the wall
C.	Near each other
D.	None of these
Answer» D. None of these

Discussion

364.	In frictional fluid flow, the quantity, (P/ρ) + (V2/2gc) + gz/gc) is___________________?
A.	Constant along a streamline
B.	Not constant along a streamline
C.	Increased in the direction of flow
D.	None of these
Answer» C. Increased in the direction of flow

Discussion

365.	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» B. Pressure

Discussion

366.	In fluid flow, the boundary layer separation cannot 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
Answer» E.

Discussion

367.	In fluid flow, cavitation is caused, if the____________________?
A.	Fluid velocity decreases to zero
B.	Total energy decreases
C.	Both A. and B.
D.	Flow pressure approaches its vapor pressure at the prevailing temperature
Answer» E.

Discussion

368.	In deriving Bernoulli’s equation, fluid is assumed to be________________?
A.	Incompressible, frictionless, steady, along a streamline
B.	Uniform, steady, incompressible, along a streamline
C.	Steady, density being pressure dependent, frictionless
D.	None of these
Answer» B. Uniform, steady, incompressible, along a streamline

Discussion

369.	In continuous fluidisation_________________?
A.	Solids are completely entrained
B.	The pressure drop is less than that for batch fluidisation
C.	There is no entrainment of solids
D.	Velocity of the fluid is very small
Answer» B. The pressure drop is less than that for batch fluidisation

Discussion

370.	In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes_______________?
A.	Less than atmospheric pressure
B.	More than liquid vapor pressure
C.	Less than liquid vapor pressure
D.	More than atmospheric pressure
Answer» D. More than atmospheric pressure

Discussion

371.	In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure ______________ the vapor pressure of the liquid at the suction temperature?
A.	Lower than
B.	Higher than
C.	Equal to
D.	None of these
Answer» C. Equal to

Discussion

372.	In case of turbulent flow of fluid through a circular pipe, the __________________?
A.	Mean flow velocity is about 0.5 times the maximum velocity
B.	Velocity profile becomes flatter and flatter with increasing Reynolds number
C.	Point of maximum instability exists at a distance of 2r/3 from the pipe wall (r = pipe radius)
D.	Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Answer» E.

Discussion

373.	In case of Venturimeter, friction losses are about _____________ percent of maximum velocity head?
A.	2
B.	8
C.	12
D.	20
Answer» B. 8

Discussion

374.	In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow ?
A.	Discharge of water by a centrifugal pump being run at a constant rpm
B.	Water flow in the suction and discharge pipe of a reciprocating pump
C.	Water discharge from a vertical vessel in which constant level is maintained
D.	Low velocity flow of a highly viscous liquid through a hydraulically smooth pipe
Answer» C. Water discharge from a vertical vessel in which constant level is maintained

Discussion

375.	In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity)?
A.	Vavg
B.	1.2 Vavg
C.	1.5 Vavg
D.	1.8 Vavg
Answer» C. 1.5 Vavg

Discussion

376.	In case of supersonic flow of a fluid through pipeline, the ‘Mach number’ is__________________?
A.	0
B.	1
C.	< 1
D.	> 1
Answer» E.

Discussion

377.	In case of laminar flow of fluid through a circular pipe, the__________________?
A.	Shear stress over the cross-section is proportional to the distance from the surface of the pipe
B.	Surface of velocity distribution is a paraboloid of revolution, whose volume equals half the volume of circumscribing cylinder
C.	Velocity profile varies hyperbolically and the shear stress remains constant over the crosssection
D.	Average flow occurs at a radial distance of 0.5 r from the centre of the pipe (r = pipe radius)
Answer» C. Velocity profile varies hyperbolically and the shear stress remains constant over the crosssection

Discussion

378.	In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where M = molecular weight of the gas) ?
A.	1/√M
B.	√M
C.	1/M
D.	M
Answer» B. √M

Discussion

379.	In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where, T = absolute temperature) ?
A.	1/√T
B.	1/T
C.	√T
D.	T
Answer» D. T

Discussion

380.	In case of hydraulically smooth pipe, the resistance to flow depends only on the Reynolds number, whereas for a hydraulically rough pipe, the resistance to flow is governed by the relative roughness. Two pipes are said to have the same hydraulic roughness, when they have equal values of___________________?
A.	Relative roughness
B.	Absolute roughness
C.	Friction co-efficient for flows at equal Reynold number
D.	All A., B. & C.
Answer» D. All A., B. & C.

Discussion

381.	In case of end to end connection of two or more pipes in series, the ______________ each pipe?
A.	Same rate of flow passes through
B.	Head loss is same through
C.	Rate of flow in each pipe is proportional to the length of
D.	Total flow rate is the sum of flow rate in
Answer» B. Head loss is same through

Discussion

382.	In case of Couette flow, the fluid flow is between two large flat parallel plates with___________________?
A.	Top plate moving and the bottom plate fixed
B.	Bottom plate moving and the top plate fixed
C.	Both the plates fixed
D.	Both the plates moving
Answer» B. Bottom plate moving and the top plate fixed

Discussion

383.	In case of centrifugal fan or blower, the gas capacity varies as __________________?
A.	Speed
B.	(Speed)2
C.	(Speed)3
D.	(Speed)0.5
Answer» B. (Speed)2

Discussion

384.	In case of a ____________ the energy of flow is considerably decreased downstream of the machine?
A.	Blower
B.	Turbine
C.	Centrifugal pump
D.	Centrifugal fan
Answer» C. Centrifugal pump

Discussion

385.	In case of a Rotameter, the density of the float material is _____________ that of the liquid it replaces?
A.	More than
B.	Less than
C.	Equal to
D.	Either A. or B.
Answer» B. Less than

Discussion

386.	In case of a pipe exit fitted with a nozzle, the____________________?
A.	Conversion of kinetic head to pressure head is facilitated
B.	Conversion of pressure head to kinetic head is facilitated
C.	Power transmitted through the nozzle is maximum, when the head lost due to friction in the pipe is equal to one third of the total supply head
D.	Both B. and C.
Answer» E.

Discussion

387.	In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is___________________?
A.	The velocity of sound
B.	Dependent on its cross-sectional area
C.	Dependent on fluid viscosity
D.	Dependent on fluid density
Answer» B. Dependent on its cross-sectional area

Discussion

388.	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.
Answer» E.

Discussion

389.	In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the _____________ efficiency?
A.	Manometric
B.	Mechanical
C.	Volumetric
D.	Overall
Answer» B. Mechanical

Discussion

390.	In area meter (e.g., Rotameter), with increase in the fluid flow rate, the___________________?
A.	Pressure drop increases linearly
B.	Pressure drop is almost constant
C.	Area through which fluid flows does not vary
D.	None of these
Answer» C. Area through which fluid flows does not vary

Discussion

391.	In an incompressible fluid, the density is____________________?
A.	Greatly affected by moderate changes in pressure
B.	Greatly affected only by moderate changes in temperature
C.	Not affected with moderate change in temperature & pressure
D.	Sensible to changes in both temperature & pressure
Answer» D. Sensible to changes in both temperature & pressure

Discussion

392.	In an incompressible flow of fluid, the fluid ________________?
A.	Temperature remains constant
B.	Compressibility is greater than zero
C.	Density does not change with pressure & temperature
D.	Is frictionless
Answer» D. Is frictionless

Discussion

393.	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
Answer» C. Venturimeter

Discussion

394.	In a stabilised soap bubble, pressure inside it compared to external pressure is________________?
A.	More
B.	Less
C.	Same
D.	Unpredictable
Answer» B. Less

Discussion

395.	In a fully turbulent flow (Re > 105) in a pipe of diameter ‘d’, for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is_______________?
A.	d
B.	d2
C.	d2.5
D.	d4
Answer» D. d4

Discussion

396.	In a free vortex, the_____________________?
A.	Velocity changes linearly with radial distance
B.	Flow is necessarily rotational
C.	Radial component of velocity is same everywhere
D.	Stream lines are not circular
Answer» B. Flow is necessarily rotational

Discussion

397.	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
Answer» C. Hot spots are formed

Discussion

398.	In a dry packed bed, the pressure drop will be changed by increasing the flow rate as__________________?
A.	V1.8
B.	V-0.8
C.	V
D.	V-1
Answer» B. V-0.8

Discussion

399.	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
Answer» B. x/2

Discussion

400.	If two capillary tubes of dia 0.5 mm and 1 mm are dipped in a pot containing mercury, then the rise of mercury is_________________?
A.	Same in both the tubes
B.	Greater in 1 mm dia tube
C.	Greater in 0.5 mm dia tube
D.	Zero in both the tubes
Answer» D. Zero in both the tubes

Discussion

Explore topic-wise MCQs in Chemical Engineering.

In the Newton’s law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass is ______________ the fluid viscosity?

In the low Reynolds number region, the drag force on a sphere is proportional to_______________?

In the laminar boundary layer flow over a flat plate, the ratio (δ/x) varies as: (where, ‘δ’ is the boundary layer thickness and ‘x’ is the distance from the leading edge in the direction of flow)?

In the complete turbulence zone (in rough pipes), the____________________?

In power law, δ = [A (du/dy)2 + B] then the fluid is__________________?

In parallel pipe problems, the__________________?

In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is_________________?

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?

In Newton’s law range, the drag co-efficient for the motion of spherical particle in a stationary fluid is___________________?

In magnetic flow meters, voltage generation is________________?

In laminar flow through a round tube, the discharge varies ______________________?

In isotropic turbulence, the _____________ are equal to each other?

In hindered settling, the particles are_________________________?

In frictional fluid flow, the quantity, (P/ρ) + (V2/2gc) + gz/gc) is___________________?

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

In fluid flow, the boundary layer separation cannot occur___________________?

In fluid flow, cavitation is caused, if the____________________?

In deriving Bernoulli’s equation, fluid is assumed to be________________?

In continuous fluidisation_________________?

In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes_______________?

In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure ______________ the vapor pressure of the liquid at the suction temperature?

In case of turbulent flow of fluid through a circular pipe, the __________________?

In case of Venturimeter, friction losses are about _____________ percent of maximum velocity head?

In case of unsteady fluid flow, conditions & flow pattern change with the passage of time at a position in a flow situation. Which of the following is an example of unsteady flow ?

In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity)?

In case of supersonic flow of a fluid through pipeline, the ‘Mach number’ is__________________?

In case of laminar flow of fluid through a circular pipe, the__________________?

In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where M = molecular weight of the gas) ?

In case of isentropic flow, the speed of sound in an ideal gas is proportional to (where, T = absolute temperature) ?

In case of end to end connection of two or more pipes in series, the ______________ each pipe?

In case of Couette flow, the fluid flow is between two large flat parallel plates with___________________?

In case of centrifugal fan or blower, the gas capacity varies as __________________?

In case of a ____________ the energy of flow is considerably decreased downstream of the machine?

In case of a Rotameter, the density of the float material is _____________ that of the liquid it replaces?

In case of a pipe exit fitted with a nozzle, the____________________?

In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is___________________?

In case of a centrifugal pump, the theoretical head developed is dependent on the _____________ the impeller?

In case of a centrifugal pump, the ratio of total delivered pressure to pressure developed with the impeller is called the _____________ efficiency?

In area meter (e.g., Rotameter), with increase in the fluid flow rate, the___________________?

In an incompressible fluid, the density is____________________?

In an incompressible flow of fluid, the fluid ________________?

In a/an _____________, the flow rate of fluids is obtained by measuring the difference between the impact and the static pressure?

In a stabilised soap bubble, pressure inside it compared to external pressure is________________?

In a fully turbulent flow (Re > 105) in a pipe of diameter ‘d’, for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is_______________?

In a free vortex, the_____________________?

In a fluidised bed reactor___________________?

In a dry packed bed, the pressure drop will be changed by increasing the flow rate as__________________?

If ‘x’ is the depth of flow in an open channel of large width, then the hydraulic radius is equal to________________?

If two capillary tubes of dia 0.5 mm and 1 mm are dipped in a pot containing mercury, then the rise of mercury is_________________?