A fluid is defined as one which:

is solid-like when there is no motion

deforms continuously when subjected to shear stress

Choose the best option for the Newtonian fluid

Viscosity decreases at higher shear stress

Frictionless and incompressible

Viscosity is invariant with shear stress

Viscosity decreases at higher shear stress

Viscosity increases at higher shear stress

Mercury is considered as a superior barometric fluid chiefly due to its

Negligible small vapour pressure

In the context of fluid mechanics. which of the following statements is INCORRECT?

Fluid cannot sustain any shear stress when at rest.

Fluid continues in motion under the application of shear stress.

Fluid does not deform continuously under shear stress.

Fluid cannot sustain any shear stress when at rest.

Fluid deforms under very small shear stress.

In a static fluid, _______.

Resistance to shear stress is small

A plate 0.02 mm distant from a fixed plate moves at 20 cm/s requires a shear stress of 4 N/m2 to maintain this speed. Viscosity of fluid available inside these plates is:

\(4 \times {10^{ - 5}}\frac{{Ns}}{{{m^2}}}\)

\(4 \times {10^{ - 4}}\frac{{Ns}}{{{m^2}}}\)

A solid sphere of radius, r, and made of material with density ρs, is moving through the atmosphere (constant pressure, p) with a velocity, v. The net force ONLY due to atmospheric pressure (Fp) acting on the sphere at any time, t, is

\(\frac{4}{3}\pi {r^3}{\rho _s}\frac{{dv}}{{dt}}\)

Mercury is a suitable fluid for a barometer because it:

Has very low vapour pressure at room temperature

Has high vapour pressure at room temperature

In an ideal fluid flow, the:

pressure increases linearly with depth

surface tension forces are zero.

pressure increases linearly with depth

The viscosity as a property of fluid indicates:

Variation of thermal conductivity with temperature

Variation of static pressure with height in the liquid body

How well the fluid will adhere to a metal surface

Its resistance to flow over the surface

Variation of thermal conductivity with temperature

88 + Mcqs in Properties Of Fluids in Fluid Mechanics Page 1 McqOptions

1.	A fluid is defined as one which:
A.	is solid-like when there is no motion
B.	deforms continuously when subjected to shear stress
C.	cannot withstand shear
D.	can withstand elongation
Answer» C. cannot withstand shear

Discussion

2.	Consider the following properties:1. Energy5. Pressure2. Entropy6. Temperature3. Gibbs energy7. Viscosity4. Volume8. ElasticityWhich of the above are intensive properties?
A.	1, 3, 5, 6
B.	5, 6, 7, 8
C.	1, 3, 5, 6, 7, 8
D.	4, 5, 6 8
Answer» C. 1, 3, 5, 6, 7, 8

Discussion

3.	Kinematic viscosity is expressed in
A.	stoke
B.	m2/sec
C.	cm2/sec
D.	all of the above
Answer» E.

Discussion

4.	Milk mixes with water due to
A.	Very good cohesion
B.	Very good adhesion
C.	Very good surface tension
D.	Very good vapour pressure
Answer» C. Very good surface tension

Discussion

5.	Fluids undergo volume change under external pressure due to
A.	Plasticity
B.	Viscosity
C.	Tenacity
D.	Compressibility
Answer» E.

Discussion

6.	Choose the best option for the Newtonian fluid
A.	Frictionless and incompressible
B.	Viscosity is invariant with shear stress
C.	Viscosity decreases at higher shear stress
D.	Viscosity increases at higher shear stress
Answer» C. Viscosity decreases at higher shear stress

Discussion

7.	How many poise is one pascal second?
A.	12
B.	13
C.	14
D.	10
Answer» E.

Discussion

8.	A plate 0.025 mm distant from a fixed plate moves at 60 cm/s and requires a force of 0.2 kgf/m2 to maintain this speed. The dynamic viscosity of the fluid between the plates will be nearly
A.	9.2 × 10-10kgfs/cm2
B.	8.3 × 10-10kgfs/cm2
C.	7.4 × 10-10kgfs/cm2
D.	6.5 × 10-10kgfs/cm2
Answer» C. 7.4 × 10-10kgfs/cm2

Discussion

9.	Mercury is considered as a superior barometric fluid chiefly due to its
A.	Negligible small vapour pressure
B.	High specific heat
C.	High specific gravity
D.	Convex meniscus
Answer» B. High specific heat

Discussion

10.	An odd shaped body weighing 7.5 kg and occupying 0.01 cubic metre volume will be completely submerged in a fluid having specific gravity of _____.
A.	1
B.	1.2
C.	0.8
D.	0.75
Answer» E.

Discussion

11.	Find the surface tension in soap bubble of 40 mm diameter when the inside pressure is 2.5 N/m2 above atmospheric pressure.
A.	0.0064 N/m
B.	0.860 N/m
C.	1.265 N/m
D.	0.0125 N/m
Answer» E.

Discussion

12.	A real fluid in which the shear stress is proportional to the rate of shear strain is known as _______.
A.	Real fluid
B.	Newtonian fluid
C.	Ideal plastic fluid
D.	Compressed fluid
Answer» C. Ideal plastic fluid

Discussion

13.	In the context of fluid mechanics. which of the following statements is INCORRECT?
A.	Fluid continues in motion under the application of shear stress.
B.	Fluid does not deform continuously under shear stress.
C.	Fluid cannot sustain any shear stress when at rest.
D.	Fluid deforms under very small shear stress.
Answer» C. Fluid cannot sustain any shear stress when at rest.

Discussion

14.	In which of the following units is the kinematic viscosity of a fluid expressed?
A.	N/m2.s
B.	N.s/m2
C.	m2/s
D.	N.s/m
Answer» D. N.s/m

Discussion

15.	A small pressure difference between two points along a pipeline carrying water is to be measured using a U-tube manometer. The manometric fluid to be used is:
A.	Mercury
B.	Carbon tetrachloride
C.	Water
D.	Kerosene
Answer» C. Water

Discussion

16.	Falling drops of water become spheres due to the property of _______.
A.	Adhesion
B.	Cohesion
C.	Surface tension
D.	Viscosity
Answer» D. Viscosity

Discussion

17.	Find the mass of the part shown in figure, ρ = 10 gm/cm3 (π = 22/7).Note: All dimensions are in mm
A.	221 gm
B.	925 gm
C.	52900 gm
D.	529 gm
Answer» E.

Discussion

18.	\(\nu = 0.0022t - \frac{{1.8}}{t}\) is the equation to determine kinematic viscosity of liquids by
A.	Redwood Viscometer
B.	Engler Viscometer
C.	Saybolt universal viscometer
D.	Newton Viscometer
Answer» D. Newton Viscometer

Discussion

19.	Poise is a unit of
A.	Surface tension
B.	Viscosity
C.	Capillarity
D.	Shear stress in fluids
Answer» C. Capillarity

Discussion

20.	In a static fluid, _______.
A.	linear deformation is small
B.	Resistance to shear stress is small
C.	Only normal stress can exist
D.	Fluid pressure is small
Answer» D. Fluid pressure is small

Discussion

21.	A unidirectional fibre-epoxy composite contains 65% by volume fibre and 35% epoxy resin. If the relative density of the fibre is 1.48 and of the resin is 1.2, the percentage weight of fibre will be nearly
A.	70%
B.	75%
C.	80%
D.	85%
Answer» B. 75%

Discussion

22.	A plate 0.02 mm distant from a fixed plate moves at 20 cm/s requires a shear stress of 4 N/m2 to maintain this speed. Viscosity of fluid available inside these plates is:
A.	4 × 10-4 poise
B.	4 × 10-6 poise
C.	\(4 \times {10^{ - 5}}\frac{{Ns}}{{{m^2}}}\)
D.	\(4 \times {10^{ - 4}}\frac{{Ns}}{{{m^2}}}\)
Answer» E.

Discussion

23.	In the isothermal condition, the isothermal bulk modulus of an ideal gas is equal to ______.
A.	constant
B.	pressure
C.	temperature
D.	viscosity
Answer» C. temperature

Discussion

24.	In the given figure, which nature of fluid is represented by curve A?
A.	Newtonian
B.	Pseudo-plastic
C.	Dilatant
D.	Ideal Bingham plastic
Answer» E.

Discussion

25.	A fluid which has shear stress is proportional to the rate of shear strain is called:
A.	Real fluid
B.	Ideal plastic fluid
C.	Ideal fluid
D.	Non Newtonian fluid
Answer» B. Ideal plastic fluid

Discussion

26.	If the relationship between shear stress of a fluid is NOT linear to the velocity gradient, then the fluid is:
A.	a compressible fluid
B.	a non-Newtonian fluid
C.	an ideal fluid
D.	a Newtonian fluid
Answer» C. an ideal fluid

Discussion

27.	A small capillary tube of 3 mm inner diameter is inserted into a fluid having density 900 kg/m3 , surface tension 0.1 N/m, and contact angle 30°. The rise in the height of fluid in the capillary tube due to surface tension is
A.	111.4 mm
B.	13.078 mm
C.	89.1 mm
D.	154.1 mm
Answer» C. 89.1 mm

Discussion

28.	Fluids change the volume under external pressure due to:
A.	Plasticity
B.	Elasticity
C.	Viscosity
D.	Compressibility
Answer» E.

Discussion

29.	Pascal second is the unit of
A.	Pressure
B.	Kinematic viscosity
C.	Dynamic viscosity
D.	Surface tension
Answer» D. Surface tension

Discussion

30.	A solid sphere of radius, r, and made of material with density ρs, is moving through the atmosphere (constant pressure, p) with a velocity, v. The net force ONLY due to atmospheric pressure (Fp) acting on the sphere at any time, t, is
A.	\(\frac{4}{3}\pi {r^3}{\rho _s}\frac{{dv}}{{dt}}\)
B.	zero
C.	πr2p
D.	4π2p
Answer» C. πr2p

Discussion

31.	Mercury is a suitable fluid for a barometer because it:
A.	Has very low vapour pressure at room temperature
B.	Wets the glass surface
C.	Has a low boiling point
D.	Has high vapour pressure at room temperature
Answer» B. Wets the glass surface

Discussion

32.	If the surface tension of a soap air interface is 0.09 N/m, the difference between the internal and external pressure in the sap bubble of 3 cm diameter is
A.	22
B.	20
C.	24
D.	30
E.	36
Answer» D. 30

Discussion

33.	A real fluid in which the shear stress is directly proportional to the rate of shear strain is known as:
A.	ideal plastic fluid
B.	ideal fluid
C.	non-Newtonian fluid
D.	Newtonian fluid
E.	non-ideal fluid
Answer» E. non-ideal fluid

Discussion

34.	A fluid which is incompressible and has no viscosity is known as a/an:
A.	Newtonian fluid
B.	non-Newtonian fluid
C.	ideal fluid
D.	ideal plastic fluid
E.	real fluid
Answer» D. ideal plastic fluid

Discussion

35.	Paper pulp can be regarded as
A.	Bingham plastic fluid
B.	Dilatant fluid
C.	Newtonian fluid
D.	Pseudo plastic fluid
Answer» E.

Discussion

36.	In CGS system, the unit of kinematic viscosity is stoke, where 1 stoke =_____.
A.	106 cm3/s
B.	10-2 m2
C.	104 cm3/s
D.	10-4 m2/s
Answer» E.

Discussion

37.	In an ideal fluid flow, the:
A.	surface tension forces are zero.
B.	pressure is equal everywhere.
C.	Viscosity is zero.
D.	pressure increases linearly with depth
Answer» D. pressure increases linearly with depth

Discussion

38.	_______ is the unit of relative density.
A.	gm/cc
B.	m/s
C.	kg/cm2
D.	None of these
Answer» E.

Discussion

39.	If the density of a liquid is 50 kg/m3, then specific volume of liquid is
A.	0.02 m3/kg
B.	0.05 m3/kg
C.	400 m3/kg
D.	500 m3/kg
Answer» B. 0.05 m3/kg

Discussion

40.	The viscosity as a property of fluid indicates:
A.	Variation of static pressure with height in the liquid body
B.	How well the fluid will adhere to a metal surface
C.	Its resistance to flow over the surface
D.	Variation of thermal conductivity with temperature
Answer» D. Variation of thermal conductivity with temperature

Discussion

41.	A fan supplies 250 CFM air flow rate. It is equal to____m3/s.
A.	0.095
B.	0.118
C.	0.127
D.	0.175
Answer» C. 0.127

Discussion

42.	Flow of air can be considered to be incompressible within 1% error if the mach number of flow is less than _____.
A.	0.4
B.	0.6
C.	0.1
D.	0.3
Answer» E.

Discussion

43.	Pressure intensity inside the soap bubble is(where σ = Surface tension, d = diameter of bubble)
A.	P = 8σ/d
B.	P = 2σ/d
C.	P = 4σ/d
D.	P = σ/d
Answer» B. P = 2σ/d

Discussion

44.	If pressure at any point in the liquid approaches the vapor pressure, liquid starts vaporising and creates pockets or bubbles of dissolved gases and vapours. This phenomenon is ________.
A.	Surface tension
B.	Adhesion
C.	Vaporisation
D.	Cavitation
Answer» E.

Discussion

45.	A fluid, in which shear stress is more than the yield value and shear stress is proportional to the rate of shear strain is known as:
A.	Newtonian fluid
B.	Ideal Plastic Fluid
C.	Real Fluid
D.	Ideal fluid
Answer» C. Real Fluid

Discussion

46.	If one liter of a fluid has a mass of 7.5 kg then its specific gravity is:
A.	0.75
B.	7.5
C.	75
D.	750
Answer» C. 75

Discussion

47.	Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called _____.
A.	Adhesion
B.	Cohesion
C.	Viscosity
D.	Compressibility
Answer» B. Cohesion

Discussion

48.	Dynamic viscosity has the dimensions as
A.	MLT-1
B.	ML-1T-1
C.	ML-1T-2
D.	M-1L-1T-1
Answer» C. ML-1T-2

Discussion

49.	In the CGS unit, dynamic viscosity is expressed as
A.	poise
B.	Pa-s
C.	stokes
D.	None of the above
Answer» B. Pa-s

Discussion

50.	Density of an ideal fluid is always _____
A.	constant
B.	zero
C.	decreasing
D.	increasing
Answer» B. zero

Discussion

Explore topic-wise MCQs in Fluid Mechanics.

A fluid is defined as one which:

Consider the following properties:1. Energy5. Pressure2. Entropy6. Temperature3. Gibbs energy7. Viscosity4. Volume8. ElasticityWhich of the above are intensive properties?

Kinematic viscosity is expressed in

Milk mixes with water due to

Fluids undergo volume change under external pressure due to

Choose the best option for the Newtonian fluid

How many poise is one pascal second?

A plate 0.025 mm distant from a fixed plate moves at 60 cm/s and requires a force of 0.2 kgf/m2 to maintain this speed. The dynamic viscosity of the fluid between the plates will be nearly

Mercury is considered as a superior barometric fluid chiefly due to its

An odd shaped body weighing 7.5 kg and occupying 0.01 cubic metre volume will be completely submerged in a fluid having specific gravity of _____.

Find the surface tension in soap bubble of 40 mm diameter when the inside pressure is 2.5 N/m2 above atmospheric pressure.

A real fluid in which the shear stress is proportional to the rate of shear strain is known as _______.

In the context of fluid mechanics. which of the following statements is INCORRECT?

In which of the following units is the kinematic viscosity of a fluid expressed?

A small pressure difference between two points along a pipeline carrying water is to be measured using a U-tube manometer. The manometric fluid to be used is:

Falling drops of water become spheres due to the property of _______.

Find the mass of the part shown in figure, ρ = 10 gm/cm3 (π = 22/7).Note: All dimensions are in mm

\(\nu = 0.0022t - \frac{{1.8}}{t}\) is the equation to determine kinematic viscosity of liquids by

Poise is a unit of

In a static fluid, _______.

A unidirectional fibre-epoxy composite contains 65% by volume fibre and 35% epoxy resin. If the relative density of the fibre is 1.48 and of the resin is 1.2, the percentage weight of fibre will be nearly

A plate 0.02 mm distant from a fixed plate moves at 20 cm/s requires a shear stress of 4 N/m2 to maintain this speed. Viscosity of fluid available inside these plates is:

In the isothermal condition, the isothermal bulk modulus of an ideal gas is equal to ______.

In the given figure, which nature of fluid is represented by curve A?

A fluid which has shear stress is proportional to the rate of shear strain is called:

If the relationship between shear stress of a fluid is NOT linear to the velocity gradient, then the fluid is:

A small capillary tube of 3 mm inner diameter is inserted into a fluid having density 900 kg/m3 , surface tension 0.1 N/m, and contact angle 30°. The rise in the height of fluid in the capillary tube due to surface tension is

Fluids change the volume under external pressure due to:

Pascal second is the unit of

A solid sphere of radius, r, and made of material with density ρs, is moving through the atmosphere (constant pressure, p) with a velocity, v. The net force ONLY due to atmospheric pressure (Fp) acting on the sphere at any time, t, is

Mercury is a suitable fluid for a barometer because it:

If the surface tension of a soap air interface is 0.09 N/m, the difference between the internal and external pressure in the sap bubble of 3 cm diameter is

A real fluid in which the shear stress is directly proportional to the rate of shear strain is known as:

A fluid which is incompressible and has no viscosity is known as a/an:

Paper pulp can be regarded as

In CGS system, the unit of kinematic viscosity is stoke, where 1 stoke =_____.

In an ideal fluid flow, the:

_______ is the unit of relative density.

If the density of a liquid is 50 kg/m3, then specific volume of liquid is

​The viscosity as a property of fluid indicates:

A fan supplies 250 CFM air flow rate. It is equal to____m3/s.

Flow of air can be considered to be incompressible within 1% error if the mach number of flow is less than _____.

Pressure intensity inside the soap bubble is(where σ = Surface tension, d = diameter of bubble)

If pressure at any point in the liquid approaches the vapor pressure, liquid starts vaporising and creates pockets or bubbles of dissolved gases and vapours. This phenomenon is ________.

A fluid, in which shear stress is more than the yield value and shear stress is proportional to the rate of shear strain is known as:

If one liter of a fluid has a mass of 7.5 kg then its specific gravity is:

Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called _____.

Dynamic viscosity has the dimensions as

In the CGS unit, dynamic viscosity is expressed as

Density of an ideal fluid is always _____

The viscosity as a property of fluid indicates: