The velocity corresponding to Reynold number of 2000 is called
Sub-sonic velocity
Super-sonic velocity
Lower critical velocity
Higher critical velocity
Correct Answer :
C. Lower critical velocity
Related Questions
The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as
Meta center
Center of pressure
Center of buoyancy
Center of gravity
Which of the following meters is not associated with viscosity?
Red wood
Say bolt
Engler
Orsat
Which of the following statement is wrong?
A flow whose streamline is represented by a curve is called two dimensional flow.
The total energy of a liquid particle is the sum of potential energy, kinetic energy and pressure energy.
The length of divergent portion in a Venturimeter is equal to the convergent portion.
A pitot tube is used to measure the velocity of flow at the required point in a pipe.
If the depth of water in an open channel is greater than the critical depth, the flow is called
Critical flow
Turbulent flow
Tranquil flow
Torrential flow
According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain.
Equal to
Directly proportional
Inversely proportional
None of these
The flow in a pipe is neither laminar nor turbulent when Reynold number is
Less than 2000
Between 2000 and 2800
More than 2800
None of these
Poise is the unit of
Surface tension
Capillarity
Viscosity
Shear stress in fluids
A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface.
H/3
H/2
2H/3
3H/4
The intensity of pressure at any point, in a liquid, is __________ to the depth of liquid from the surface.
Equal
Directly proportional
Inversely proportional
None of these
The resultant of all normal pressures acts
At C.G. of body
At center of pressure
Vertically upwards
At metacentre
Barometer is used to measure
Velocity of liquid
Atmospheric pressure
Pressure in pipes and channels
Difference of pressure between two points in a pipe
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
Falling drops of water become spheres due to the property of
Adhesion
Cohesion
Surface tension
Viscosity
The centre of gravity of the volume of the liquid displaced is called
Centre of pressure
Centre of buoyancy
Metacentre
None of these
Cavitation is caused by
High velocity
High pressure
Weak material
Low pressure
The two important forces for a floating body are
Buoyancy, gravity
Buoyancy, pressure
Buoyancy, inertial
Inertial, gravity
Gauge pressure at a point is equal to the absolute pressure __________ the atmospheric pressure.
Plus
Minus
Divide
Multiply
The liquid used in manometers should have
Low density
High density
Low surface tension
High surface tension
When the Venturimeter is inclined, then for a given flow it will show __________ reading.
Same
More
Less
None of these
In a venturi-flume, the flow takes place at
Atmospheric pressure
Gauge pressure
Absolute pressure
None of these
Mach number is significant in
Supersonics, as with projectiles 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 force, and wave making effects, as with ship's hulls
All of the above
A tank of uniform cross-sectional area (A) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to bring the liquid level from H1 to H2 will be
2A × √H₁/Cd × a × √(2g)
2A × √H₂/Cd × a × √(2g)
2A × (√H₁ - √H₂)/Cd × a × √(2g)
2A × (√H3/2 - √H3/2)/Cd × a × √(2g)
A flow whose streamline is represented by a curve, is called
One-dimensional flow
Two-dimensional flow
Three-dimensional flow
Four-dimensional flow
Viscosity of water in comparison to mercury is
Higher
Lower
Same
Higher/lower depending on temperature
Capillary action is due to the
Surface tension
Cohesion of the liquid
Adhesion of the liquid molecules and the molecules on the surface of a solid
All of the above
The kinematic viscosity is the
Ratio of absolute viscosity to the density of the liquid
Ratio of density of the liquid to the absolute viscosity
Product of absolute viscosity and density of the liquid
Product of absolute viscosity and mass of the liquid
The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to
2100
2700
10,000
21,000
The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
Half the depth
Half the breadth
Twice the depth
Twice the breadth
Liquids transmit pressure equally in all the directions. This is according to
Boyle's law
Archimedes principle
Pascal's law
Newton's formula
The coefficient of discharge for an external mouthpiece is
0.375
0.5
0.707
0.855