Reynolds number is significant in
Supersonics, as with projectile and jet propulsion
Full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
Simultaneous motion through two fluids where there is a surface of discontinuity, gravity forces, and wave making effect, as with ship's hulls
All of the above
Correct Answer :
B. Full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
Related Questions
In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than
Frictional force
Viscosity
Surface friction
All of the above
Water is a __________ fluid.
Real
Ideal
Newtonian
Non-Newtonian
When a liquid is flowing through a pipe, the velocity of the liquid is
Maximum at the centre and minimum near the walls
Minimum at the centre and maximum near the walls
Zero at the centre and maximum near the walls
Maximum at the centre and zero near the walls
Principle of similitude forms the basis of
Comparing two identical equipments
Designing models so that the result can be converted to prototypes
Comparing similarity between design and actual equipment
Hydraulic designs
The surface tension of mercury at normal temperature compared to that of water is
More
Less
Same
More or less depending on size of glass tube
The liquid used in manometers should have
Low density
High density
Low surface tension
High surface tension
According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
The weight of the body
More than the weight of the body
Less than the weight of the body
Weight of the fluid displaced by the body
Gauge pressure at a point is equal to the absolute pressure __________ the atmospheric pressure.
Plus
Minus
Divide
Multiply
For a floating body to be in equilibrium
Meta centre should be above e.g.
Centre of buoyancy and e.g. must lie on same vertical plane
A righting couple should be formed
All of the above
The velocity at which the flow changes from laminar flow to turbulent flow is called
Critical velocity
Velocity of approach
Sub-sonic velocity
Super-sonic velocity
In an immersed body, centre of pressure is
At the centre of gravity
Above the centre of gravity
Below be centre of gravity
Could be above or below e.g. depending on density of body and liquid
The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is
Directly proportional to (radius)2
Inversely proportional to (radius)2
Directly proportional to (radius)4
Inversely proportional to (radius)4
The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the Centroid, if
The area is horizontal
The area is vertical
The area is inclined
All of the above
A flow in which the viscosity of fluid is dominating over the inertia force is called
Steady flow
Unsteady flow
Laminar flow
Turbulent flow
The depth of the centre of pressure on a vertical rectangular gate 8 m wide and 6 m high, when the water surface coincides with the top of the gate, is
2.4 m
3.0 m
4.0 m
5.0 m
Unit of surface tension is
Energy/unit area
Velocity/unit area
Both of the above
It has no units
The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v = Velocity of the liquid in the pipe, μ = Viscosity of the liquid, and w = Specific weight of the flowing liquid)
4μvl/wd²
8μvl/wd²
16μvl/wd²
32μvl/wd²
All the terms of energy in Bernoulli's equation have dimension of
Energy
Work
Mass
Length
One litre of water occupies a volume of
100 cm3
250 cm3
500 cm3
1000 cm3
A pipe of length more than double the diameter of orifice fitted externally or internally to the orifice is called a
Notch
Weir
Mouthpiece
Nozzle
Reynold's number is the ratio of inertia force to
Pressure force
Elastic force
Gravity force
Viscous force
The centre of pressure acts __________ the centre of gravity of immersed surface.
At
Above
Below
None of these
Poise is the unit of
Surface tension
Capillarity
Viscosity
Shear stress in fluids
The ratio of absolute viscosity to mass density is known as
Specific viscosity
Viscosity index
Kinematic viscosity
Coefficient of viscosity
The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the submerged body is called
Up-thrust
Reaction
Buoyancy
Metacentre
A weir is said to be broad crested weir, if the width of the crest of the weir is ________ half the height of water above the weir crest.
Equal to
Less than
More than
None of these
A pressure of 25 m of head of water is equal to
25 kN/ m²
245 kN/ m²
2500 kN/m²
2.5 kN/ m²
Which of the following instruments is used to measure flow on the application of Bernoulli's theorem?
Venturimeter
Orifice plate
Nozzle
All of the above
When a cylindrical vessel containing liquid is resolved, the surface of the liquid takes the shape of
A triangle
A paraboloid
An ellipse
None of these
The buoyancy depends upon the
Weight of the liquid displaced
Pressure with which the liquid is displaced
Viscosity of the liquid
Compressibility of the liquid