Match the dimensionless parameters in Group – I with the corresponding ratio In Group – IIGroup IIGroup – IIP. Mach number1. Ratio of inertia force and gravitational forceQ. Reynolds number2. Ratio of fluid velocity and velocity of soundR. Weber number3. Ratio of inertia force and viscous forceS. Froude number4 Ratio of inertia force and surface tension force

P – 1, Q – 3, R – 3, S – 4

P -3, Q – 3, R – 4, S – 1

P -3, Q – 4, R – 2, S – 1

P – 2, Q – 3, R – 4, S – 1

P – 1, Q – 3, R – 3, S – 4

Hydraulic ram is a device used

lift water without electric motor

for pumping small quantity of water high head, when large quantity of water at small head is available

A flow is said to be supersonic, if the

If the velocity of flow is very high

If the discharge id difficult to measure

Dynamic similarity exists when the model and the prototype have the same:

Length scale ratio and time scale ratio

Length scale ratio and velocity scale ratio

Length scale ratio, time scale ratio and velocity scale ratio

Length scale ratio, velocity scale ratio and force scale ratio

Euler's dimensionless number relates the following:

Viscous force and buoyancy force

Viscous force and inertial force

Inertial force and gravity force

Pressure force and inertial force

If a centrifugal pump has an impeller speed of N (in rpm) discharge Q (in m3/s) and the total head H (in m), the expression for the specific speed Ns of the pump is given by

${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}$

${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.5}}}}$

${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{\rm{H}}}$

${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.75}}}}$

${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}$

Froude number is significant in:

Supersonics, as with projectile and jet propulsion

Full immersion or completely enclosed flow, as with pipes, air crafts wings, nozzles, etc.

Simultaneous motion through two fluids where there is a surface discontinuity. Gravity forces and wave-making effect, as with ship’s hulls

A hydraulic intensifier normally consists of _____.

A cylinder, a piston, storage tank and control valve

Two cylinders, two rams and a storage device

A cylinder, a piston, storage tank and control valve

A dimensionless group formed with variables: ρ (mass density), μ (dynamic viscosity), g (gravitational acceleration) and D (characteristic length) is:

$\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}$

$\frac{{{{\rm{D}}^{\frac{3}{2}}}}}{{{\rm{\rho \mu g}}}}$

$\frac{{\rm{\mu }}}{{{\rm{\rho }}{{\rm{g}}^{\frac{1}{2}}}{{\rm{D}}^{\frac{3}{2}}}}}$

$\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}$

$\frac{{\rm{\mu }}}{{{{\rm{\rho }}^{\frac{1}{2}}}{\rm{D}}{{\rm{g}}^{\frac{1}{2}}}}}$

Identify the incorrect statement, from the following options:The specific speed of a hydraulic turbine (given N = RPM, P = power output, H = input head to a turbine design, NS is its specific speed)_____.

Gives RPM of a turbine with the same hydraulic efficiency as the original, i.e., same design

RPM of a geometrically and dynamically similar turbine which will develop 1 kW power under 1 m

Principles of similitude form basis of

Comparing two identical equipments

Comparing similarity between design and actual equipment

Design and testing of prototype based on results of model

Euler number is related to

Inertia force and elastic force

Inertia force and pressure force

Inertia force and elastic force

Inertia force and viscous force

Inertia force and gravity force

Mach angle α and Mach number M are related as

$\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)$

$M = {\sin ^{ - 1}}\left( {\frac{1}{\alpha }} \right)$

$\alpha = {\cos ^{ - 1}}\left( {\sqrt {\frac{{{M^2} - 1}}{{{M^2}}}} } \right)$

$\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)$

$\alpha = cose{c^{ - 1}}\left( {\frac{1}{M}} \right)$

According to Froude’s model law

$\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}$

$\frac{{{v_p} \;\times \;{L_p}}}{{{v_p}}} = \frac{{{v_m} \;\times\; {L_m}}}{{{v_m}}}$

$\frac{V_m}{\sqrt{L_m g_m}} = \frac{V_p}{\sqrt{L_p g_p}}$

$\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}$

$\frac{V_m{\rho_m L_m}}{{\sqrt{\sigma_m}}} = \frac{V_p{\rho_p L_p}}{{\sqrt{\sigma_p}}}$

What is the formula for elastic force?

Elastics stress* Elastic strain

56 + Mcqs in Model Analysis in Fluid Mechanics Page 1 McqOptions

1.	For a dynamic similarity between a model and a prototype, the ratio of their forces in the model and the prototype must be equal.
A.	True
B.	False
Answer» B. False

Discussion

2.	The similarity between the forces of model and prototype is ________
A.	Dynamic similarity
B.	Potential similarity
C.	Kinematic similarity
D.	Design similarity
Answer» B. Potential similarity

Discussion

3.	Match the dimensionless parameters in Group – I with the corresponding ratio In Group – IIGroup IIGroup – IIP. Mach number1. Ratio of inertia force and gravitational forceQ. Reynolds number2. Ratio of fluid velocity and velocity of soundR. Weber number3. Ratio of inertia force and viscous forceS. Froude number4 Ratio of inertia force and surface tension force
A.	P -3, Q – 3, R – 4, S – 1
B.	P -3, Q – 4, R – 2, S – 1
C.	P – 2, Q – 3, R – 4, S – 1
D.	P – 1, Q – 3, R – 3, S – 4
Answer» D. P – 1, Q – 3, R – 3, S – 4

Discussion

4.	Hydraulic ram is a device used
A.	to accelerate water flow
B.	lift water without electric motor
C.	for lifting heavy load
D.	for pumping small quantity of water high head, when large quantity of water at small head is available
Answer» E.

Discussion

5.	Froude number is important for:
A.	Unsteady flow
B.	Compressible flow
C.	Free surface flow
D.	Viscous flow
Answer» D. Viscous flow

Discussion

6.	If the Mach number for a compressible fluid flow is less than 1, the flow is
A.	Sonic
B.	Supersonic
C.	Subsonic
D.	None of the above
Answer» D. None of the above

Discussion

7.	A flow is said to be supersonic, if the
A.	If the velocity of flow is very high
B.	Mach number is between 1 and 6
C.	Mach number is more than 6
D.	If the discharge id difficult to measure
Answer» C. Mach number is more than 6

Discussion

8.	A 2 m wide rectangular channel carries a discharge of 10 m3/s. What would be the depth of flow if the Froude number of the flow is 2.0 ?
A.	1.72 m
B.	1.36 m
C.	0.86 m
D.	0.68 m
Answer» D. 0.68 m

Discussion

9.	In model similarity, if gravitational and inertia forces are the only important forces, then what is the discharge ratio (Note: Lr is the ratio of length dimension)?
A.	Lr 3/2
B.	Lr 1/2
C.	Lr 5/2
D.	Lr 1/3
Answer» D. Lr 1/3

Discussion

10.	Model analysis of aeroplanes and projectile moving at supersonic speed is based on.
A.	Reynold Number
B.	Froude Number
C.	Mach Number
D.	Euler Number
Answer» D. Euler Number

Discussion

11.	Air flows isentropically through a duct. At a section, the area is 0.05 m2 , velocity v = 180 m/s and temperature T = 470 K. Compute the stagnation temperature To
A.	486 K
B.	286 K
C.	556 K
D.	508 K
Answer» B. 286 K

Discussion

12.	If the Froude number in open channel flow is less than 1, then the flow is called ________.
A.	Critical flow
B.	Super - critical flow
C.	Sub - critical flow
D.	None of these
Answer» D. None of these

Discussion

13.	If the Mach number of a flow is 3, then the flow is known as-
A.	Subsonic
B.	Supersonic
C.	Sonic
D.	Laminar
Answer» C. Sonic

Discussion

14.	Model analysis is free surface flows are based on
A.	Reynolds number
B.	Froude Number
C.	Mach number
D.	Euler number
Answer» C. Mach number

Discussion

15.	A large power generating unit uses a hydraulic turbine to generate 300 kW at 1000 rpm under a head of 40 m. For initial testing, a 1 : 4 scale model of the turbine operates under a head of 10 m. The power generated by the model (in kW) will be
A.	234
B.	2.34
C.	23.4
D.	0.234
Answer» C. 23.4

Discussion

16.	A wire has a mass (0.3 ± 0.003) g, radius (0.5 ± 0.005) mm and length (6 ± 0.06) cm. The maximum percentage error in the measurement of density is
A.	1
B.	2
C.	3
D.	4
Answer» E.

Discussion

17.	Dynamic similarity exists when the model and the prototype have the same:
A.	Length scale ratio and time scale ratio
B.	Length scale ratio and velocity scale ratio
C.	Length scale ratio, time scale ratio and velocity scale ratio
D.	Length scale ratio, velocity scale ratio and force scale ratio
Answer» E.

Discussion

18.	Given power ‘P’ of a pump, the head ‘H’, the discharge ‘Q’ and specific weight ‘w’ of the liquid, dimensional analysis would lead to the result that ‘P’ is proportional to
A.	H1/2Q2 w
B.	H1/2 Qw
C.	HQ1/2 w
D.	HQw
Answer» E.

Discussion

19.	Euler's dimensionless number relates the following:
A.	Viscous force and buoyancy force
B.	Viscous force and inertial force
C.	Inertial force and gravity force
D.	Pressure force and inertial force
Answer» E.

Discussion

20.	If a centrifugal pump has an impeller speed of N (in rpm) discharge Q (in m3/s) and the total head H (in m), the expression for the specific speed Ns of the pump is given by
A.	${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.5}}}}$
B.	${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{\rm{H}}}$
C.	${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.75}}}}$
D.	${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}$
Answer» D. ${{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}$

Discussion

21.	A sphere is moving in water with a velocity of 1.6 m/s. Another sphere of twice the diameter is placed in a wind tunnel and tested with air which is 750 times less dense and 60 times less viscous than water. The velocity of air that will give dynamically similar conditions is
A.	5 m/s
B.	10 m/s
C.	20 m/s
D.	40 m/s
Answer» C. 20 m/s

Discussion

22.	In a flow condition where both viscous and gravity forces dominate and both the Froude number and Reynolds’s number are same in model and prototype, and the ratio of kinematic viscosity of model to that of the prototype is 0.0894, what is the model scale?
A.	1 : 3.3
B.	3.3 : 1
C.	5 : 1
D.	1 : 5
Answer» E.

Discussion

23.	Froude number is significant in:
A.	Supersonics, as with projectile and jet propulsion
B.	Full immersion or completely enclosed flow, as with pipes, air crafts wings, nozzles, etc.
C.	Simultaneous motion through two fluids where there is a surface discontinuity. Gravity forces and wave-making effect, as with ship’s hulls
D.	All of these
Answer» D. All of these

Discussion

24.	For similitude with gravity force, velocity ratio is
A.	1
B.	(Lr)1/2
C.	(Lr)-1
D.	Lr)3/2
Answer» C. (Lr)-1

Discussion

25.	A hydraulic intensifier normally consists of _____.
A.	Two cylinders, two rams and a storage device
B.	A cylinder and a ram
C.	Co-axial ram and two cylinders
D.	A cylinder, a piston, storage tank and control valve
Answer» D. A cylinder, a piston, storage tank and control valve

Discussion

26.	Maximum impulse will be developed in hydraulic ram when _____.
A.	When valve closes suddenly
B.	Supply pipe is long
C.	Supply pipe is short
D.	Ram chamber is large
Answer» B. Supply pipe is long

Discussion

27.	A model of a hydraulic turbine is tested at a head of 1/4th of that under which the full scale turbine works. The diameter of the model is half of that of the full scale turbine. If N is the RPM of the full scale turbine, then the RPM of the model will be
A.	N/4
B.	N/2
C.	N
D.	2N
Answer» D. 2N

Discussion

28.	For circular cylinders, with Reynolds number greater than 1000, how would the Strouhal number behave?
A.	Varies as Re1 / 6
B.	Varies as Re1 / 4
C.	Almost ≈ 0.16
D.	Constant at 0.21
Answer» E.

Discussion

29.	A model of a hydraulic turbine is tested at a head of 1/4th of that under which the full scale turbine works. The diameter of the model is half of that of the full scale turbine, if N is the RPM of the full scale turbine, then RPM of the model will be
A.	N/4
B.	N/2
C.	N
D.	2N
Answer» D. 2N

Discussion

30.	A jet travelling at supersonic speed then its Mach no (M) will be_
A.	M > 1
B.	M < 1
C.	M = 1
D.	None of these
Answer» B. M < 1

Discussion

31.	Kinematic similarity between model and prototype is the similarity of
A.	Shape
B.	Discharge/motion
C.	Stream
D.	Forces
Answer» C. Stream

Discussion

32.	A dimensionless group formed with variables: ρ (mass density), μ (dynamic viscosity), g (gravitational acceleration) and D (characteristic length) is:
A.	$\frac{{{{\rm{D}}^{\frac{3}{2}}}}}{{{\rm{\rho \mu g}}}}$
B.	$\frac{{\rm{\mu }}}{{{\rm{\rho }}{{\rm{g}}^{\frac{1}{2}}}{{\rm{D}}^{\frac{3}{2}}}}}$
C.	$\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}$
D.	$\frac{{\rm{\mu }}}{{{{\rm{\rho }}^{\frac{1}{2}}}{\rm{D}}{{\rm{g}}^{\frac{1}{2}}}}}$
Answer» C. $\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}$

Discussion

33.	A phenomenon is modeled using n dimensional variables with k primary dimensions. The number of non-dimensional variables is
A.	k
B.	n
C.	n-k
D.	n+k
Answer» D. n+k

Discussion

34.	Identify the incorrect statement, from the following options:The specific speed of a hydraulic turbine (given N = RPM, P = power output, H = input head to a turbine design, NS is its specific speed)_____.
A.	Gives RPM of a turbine with the same hydraulic efficiency as the original, i.e., same design
B.	Is NS = NP/H2
C.	NS = NP0.5/H1.25
D.	RPM of a geometrically and dynamically similar turbine which will develop 1 kW power under 1 m
Answer» C. NS = NP0.5/H1.25

Discussion

35.	A model of a golf ball is to be studied to determine the effects of the dimples. A sphere 10 times larger in diameter than an actual golf ball is used in the wind tunnel study. What speed should be selected for the model to simulate a prototype speed of 50 m/s?
A.	0.2 m/s
B.	5 m/s
C.	50 m/s
D.	10 m/s
Answer» C. 50 m/s

Discussion

36.	Froude number is the ratio of inertial force to
A.	Gravitation force
B.	Surface tension
C.	Elasticity
D.	Viscosity
Answer» B. Surface tension

Discussion

37.	Euler number is defined as the ratio of inertia forces to
A.	Viscous Force
B.	Elastic force
C.	Pressure force
D.	Gravity force
Answer» D. Gravity force

Discussion

38.	Principles of similitude form basis of
A.	Performing acceptance test
B.	Comparing two identical equipments
C.	Comparing similarity between design and actual equipment
D.	Design and testing of prototype based on results of model
Answer» E.

Discussion

39.	A flow is called hypersonic, if the Mach number is
A.	less than unity
B.	unity
C.	between 1 and 6
D.	None of the above
Answer» E.

Discussion

40.	Euler number is related to
A.	Inertia force and pressure force
B.	Inertia force and elastic force
C.	Inertia force and viscous force
D.	Inertia force and gravity force
Answer» B. Inertia force and elastic force

Discussion

41.	An experiment is conducted with a fluid of density 1 kg/m3 at 10 m/s velocity. The free stream static pressure is 100 kPa and the local static pressure is 101 kPa. What is the pressure coefficient at the location?
A.	70
B.	80
C.	20
D.	50
Answer» D. 50

Discussion

42.	In order to estimate the energy loss in a pipeline of 1 m diameter through which kerosene of specific gravity 0.80 and dynamic viscosity 0.02 poise is to be transported at the rate of 2 m3/s, model tests were conducted on a 0.1 m diameter pipe using water at 20°C. If the absolute viscosity of water at 20°C is 1.00 × 10-2 poise, then the discharge required for the model pipe would be
A.	60 l/s
B.	80 l/s
C.	120 l/s
D.	160 l/s
Answer» C. 120 l/s

Discussion

43.	Hydraulic ram is a pump which works on the principle of
A.	Water hammer
B.	Centrifugal action
C.	Reciprocating action
D.	Hydraulic press
Answer» B. Centrifugal action

Discussion

44.	A jet-propelled aircraft is flying at a speed of 1100 km/hour at t = 20°C, r = 1.4, and R = 287 J/kg K The Mach number at a point on the jet will be nearly
A.	0.3
B.	0.5
C.	0.7
D.	0.9
Answer» E.

Discussion

45.	A dimensionless group formed with the variables ρ (density), ω (angular velocity), μ (dynamic viscosity) and D (characteristic diameter) is
A.	ρμD/ω
B.	ρωμ/D2
C.	ωμD2/ρ
D.	μ/ρωD2
Answer» E.

Discussion

46.	Mach angle α and Mach number M are related as
A.	$M = {\sin ^{ - 1}}\left( {\frac{1}{\alpha }} \right)$
B.	$\alpha = {\cos ^{ - 1}}\left( {\sqrt {\frac{{{M^2} - 1}}{{{M^2}}}} } \right)$
C.	$\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)$
D.	$\alpha = cose{c^{ - 1}}\left( {\frac{1}{M}} \right)$
Answer» C. $\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)$

Discussion

47.	According to Froude’s model law
A.	$\frac{{{v_p} \;\times \;{L_p}}}{{{v_p}}} = \frac{{{v_m} \;\times\; {L_m}}}{{{v_m}}}$
B.	$\frac{V_m}{\sqrt{L_m g_m}} = \frac{V_p}{\sqrt{L_p g_p}}$
C.	$\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}$
D.	$\frac{V_m{\rho_m L_m}}{{\sqrt{\sigma_m}}} = \frac{V_p{\rho_p L_p}}{{\sqrt{\sigma_p}}}$
Answer» C. $\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}$

Discussion

48.	______ is the square root of the ratio of the inertia force to the pressure force
A.	Reynolds number
B.	Mach’s number
C.	Euler’s number
D.	Froude’s number
Answer» D. Froude’s number

Discussion

49.	FOR_A_DYNAMIC_SIMILARITY_BETWEEN_A_MODEL_AND_A_PROTOTYPE,_THE_RATIO_OF_THEIR_FORCES_IN_THE_MODEL_AND_THE_PROTOTYPE_MUST_BE_EQUAL.?$
A.	True
B.	False
Answer» B. False

Discussion

50.	What is the formula for elastic force?
A.	Elastic stress/area
B.	Elastic strain/area
C.	Elastic stress*area
D.	Elastics stress* Elastic strain
Answer» D. Elastics stress* Elastic strain

Discussion

20.	If a centrifugal pump has an impeller speed of N (in rpm) discharge Q (in m3/s) and the total head H (in m), the expression for the specific speed Ns of the pump is given by
A.	\({{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.5}}}}\)
B.	\({{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{\rm{H}}}\)
C.	\({{\rm{N}}_{\rm{s}}} = \frac{{{\rm{N}}{{\rm{Q}}^{0.5}}}}{{{{\rm{H}}^{0.75}}}}\)
D.	\({{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}\)
Answer» D. \({{\rm{N}}_{\rm{s}}} = \frac{{{\rm{NQ}}}}{{{{\rm{H}}^{0.75}}}}{\rm{\;}}\)

32.	A dimensionless group formed with variables: ρ (mass density), μ (dynamic viscosity), g (gravitational acceleration) and D (characteristic length) is:
A.	\(\frac{{{{\rm{D}}^{\frac{3}{2}}}}}{{{\rm{\rho \mu g}}}}\)
B.	\(\frac{{\rm{\mu }}}{{{\rm{\rho }}{{\rm{g}}^{\frac{1}{2}}}{{\rm{D}}^{\frac{3}{2}}}}}\)
C.	\(\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}\)
D.	\(\frac{{\rm{\mu }}}{{{{\rm{\rho }}^{\frac{1}{2}}}{\rm{D}}{{\rm{g}}^{\frac{1}{2}}}}}\)
Answer» C. \(\frac{{\rm{\mu }}}{{{\rm{\rho g}}{{\rm{D}}^{\frac{3}{2}}}}}\)

46.	Mach angle α and Mach number M are related as
A.	\(M = {\sin ^{ - 1}}\left( {\frac{1}{\alpha }} \right)\)
B.	\(\alpha = {\cos ^{ - 1}}\left( {\sqrt {\frac{{{M^2} - 1}}{{{M^2}}}} } \right)\)
C.	\(\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)\)
D.	\(\alpha = cose{c^{ - 1}}\left( {\frac{1}{M}} \right)\)
Answer» C. \(\tan \alpha \left( {\sqrt {{M^2} - 1} } \right)\)

47.	According to Froude’s model law
A.	\(\frac{{{v_p} \;\times \;{L_p}}}{{{v_p}}} = \frac{{{v_m} \;\times\; {L_m}}}{{{v_m}}}\)
B.	\(\frac{V_m}{\sqrt{L_m g_m}} = \frac{V_p}{\sqrt{L_p g_p}}\)
C.	\(\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}\)
D.	\(\frac{V_m{\rho_m L_m}}{{\sqrt{\sigma_m}}} = \frac{V_p{\rho_p L_p}}{{\sqrt{\sigma_p}}}\)
Answer» C. \(\frac{V_m}{\sqrt{p_m }} = \frac{V_p}{\sqrt{p_p }}\)

Explore topic-wise MCQs in Fluid Mechanics.

For a dynamic similarity between a model and a prototype, the ratio of their forces in the model and the prototype must be equal.

The similarity between the forces of model and prototype is ________

Hydraulic ram is a device used

Froude number is important for:

If the Mach number for a compressible fluid flow is less than 1, the flow is

A flow is said to be supersonic, if the

A 2 m wide rectangular channel carries a discharge of 10 m3/s. What would be the depth of flow if the Froude number of the flow is 2.0 ?

In model similarity, if gravitational and inertia forces are the only important forces, then what is the discharge ratio (Note: Lr is the ratio of length dimension)?

Model analysis of aeroplanes and projectile moving at supersonic speed is based on.

Air flows isentropically through a duct. At a section, the area is 0.05 m2 , velocity v = 180 m/s and temperature T = 470 K. Compute the stagnation temperature To

If the Froude number in open channel flow is less than 1, then the flow is called ________.

If the Mach number of a flow is 3, then the flow is known as-

Model analysis is free surface flows are based on

A large power generating unit uses a hydraulic turbine to generate 300 kW at 1000 rpm under a head of 40 m. For initial testing, a 1 : 4 scale model of the turbine operates under a head of 10 m. The power generated by the model (in kW) will be

A wire has a mass (0.3 ± 0.003) g, radius (0.5 ± 0.005) mm and length (6 ± 0.06) cm. The maximum percentage error in the measurement of density is

Dynamic similarity exists when the model and the prototype have the same:

Given power ‘P’ of a pump, the head ‘H’, the discharge ‘Q’ and specific weight ‘w’ of the liquid, dimensional analysis would lead to the result that ‘P’ is proportional to

Euler's dimensionless number relates the following:

If a centrifugal pump has an impeller speed of N (in rpm) discharge Q (in m3/s) and the total head H (in m), the expression for the specific speed Ns of the pump is given by

A sphere is moving in water with a velocity of 1.6 m/s. Another sphere of twice the diameter is placed in a wind tunnel and tested with air which is 750 times less dense and 60 times less viscous than water. The velocity of air that will give dynamically similar conditions is

In a flow condition where both viscous and gravity forces dominate and both the Froude number and Reynolds’s number are same in model and prototype, and the ratio of kinematic viscosity of model to that of the prototype is 0.0894, what is the model scale?

Froude number is significant in:

For similitude with gravity force, velocity ratio is

A hydraulic intensifier normally consists of _____.

Maximum impulse will be developed in hydraulic ram when _____.

A model of a hydraulic turbine is tested at a head of 1/4th of that under which the full scale turbine works. The diameter of the model is half of that of the full scale turbine. If N is the RPM of the full scale turbine, then the RPM of the model will be

For circular cylinders, with Reynolds number greater than 1000, how would the Strouhal number behave?

A model of a hydraulic turbine is tested at a head of 1/4th of that under which the full scale turbine works. The diameter of the model is half of that of the full scale turbine, if N is the RPM of the full scale turbine, then RPM of the model will be

A jet travelling at supersonic speed then its Mach no (M) will be_

Kinematic similarity between model and prototype is the similarity of

A dimensionless group formed with variables: ρ (mass density), μ (dynamic viscosity), g (gravitational acceleration) and D (characteristic length) is:

A phenomenon is modeled using n dimensional variables with k primary dimensions. The number of non-dimensional variables is

Identify the incorrect statement, from the following options:The specific speed of a hydraulic turbine (given N = RPM, P = power output, H = input head to a turbine design, NS is its specific speed)_____.

A model of a golf ball is to be studied to determine the effects of the dimples. A sphere 10 times larger in diameter than an actual golf ball is used in the wind tunnel study. What speed should be selected for the model to simulate a prototype speed of 50 m/s?

Froude number is the ratio of inertial force to

Euler number is defined as the ratio of inertia forces to

Principles of similitude form basis of

A flow is called hypersonic, if the Mach number is

Euler number is related to

An experiment is conducted with a fluid of density 1 kg/m3 at 10 m/s velocity. The free stream static pressure is 100 kPa and the local static pressure is 101 kPa. What is the pressure coefficient at the location?

Hydraulic ram is a pump which works on the principle of

A jet-propelled aircraft is flying at a speed of 1100 km/hour at t = 20°C, r = 1.4, and R = 287 J/kg K The Mach number at a point on the jet will be nearly

A dimensionless group formed with the variables ρ (density), ω (angular velocity), μ (dynamic viscosity) and D (characteristic diameter) is

Mach angle α and Mach number M are related as

According to Froude’s model law

______ is the square root of the ratio of the inertia force to the pressure force

FOR_A_DYNAMIC_SIMILARITY_BETWEEN_A_MODEL_AND_A_PROTOTYPE,_THE_RATIO_OF_THEIR_FORCES_IN_THE_MODEL_AND_THE_PROTOTYPE_MUST_BE_EQUAL.?$

What is the formula for elastic force?