When the Mach number is more than 6, the flow is called
Sub-sonic flow
Sonic flow
Super-sonic flow
Hyper-sonic flow
Correct Answer :
D. Hyper-sonic flow
Related Questions
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
Resultant pressure of the liquid in the case of an immersed body acts through
Centre of gravity
Centre of pressure
Metacentre
Centre of buoyancy
The velocity of jet of water travelling out of opening in a tank filled with water is proportional to
Head of water (h)
h²
V/T
h/2
The loss of head at entrance in a pipe is (where v = Velocity of liquid in the pipe)
v²/2g
0.5v²/2g
0.375v²/2g
0.75v²/2g
Dynamic viscosity of most of the liquids with rise in temperature
Increases
Decreases
Remain unaffected
Unpredictable
For pipes, laminar flow occurs when Reynolds number is
Less than 2000
Between 2000 and 4000
More than 4000
Less than 4000
Which of the following instrument can be used for measuring speed of an aeroplane?
Venturimeter
Orifice plate
Pitot tube
Rotameter
The length of the divergent cone in a Venturimeter is __________ that of the convergent cone.
Equal to
Double
Three to four times
Five to six times
In one dimensional flow, the flow
Is steady and uniform
Takes place in straight line
Takes place in curve
Takes place in one direction
A fluid in equilibrium can't sustain
Tensile stress
Compressive stress
Shear stress
Bending stress
For a floating body to be in stable equilibrium, its metacentre should be
Below the center of gravity
Below the center of buoyancy
Above the center of buoyancy
Above the center of gravity
The flow of water through the hole in the bottom of a wash basin is an example of
Steady flow
Uniform flow
Free vortex
Forced vortex
The total head of a liquid particle in motion is equal to
Pressure head + kinetic head + potential head
Pressure head - (kinetic head + potential head)
Potential head - (pressure head + kinetic head)
Kinetic head - (pressure head + potential head)
The hydraulic mean depth or the hydraulic radius is the ratio of
Area of flow and wetted perimeter
Wetted perimeter and diameter of pipe
Velocity of flow and area of flow
None of these
The specific gravity of water is taken as
0.001
0.01
0.1
1
The pressure of fluid due to hammer blow is
Directly proportional to density of fluid
Inversely proportional to density of fluid
Directly proportional to (density)1/2 of fluid
Inversely proportional to (density)1/2 of fluid
A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water?
10 m/sec
25 m/sec
2 m/sec
50 m/sec
The most efficient section of a channel is
Triangular
Rectangular
Square
Trapezoidal
Piezometer is used to measure
Pressure in pipe, channels etc.
Atmospheric pressure
Very low pressures
Difference of pressure between two points
The bulk modulus of elasticity with increase in pressure
Increases
Decreases
Remain constant
Increases first up to certain limit and then decreases
A flow whose streamline is represented by a curve, is called
One-dimensional flow
Two-dimensional flow
Three-dimensional flow
Four-dimensional flow
The Euler's equation for the motion of liquids is based upon the assumption that
The fluid is non - viscous, homogeneous and incompressible
The velocity of flow is uniform over the section
The flow is continuous, steady and along the stream line
All of the above
The total energy line lies over the centre line of the pipe by an amount equal to
Pressure head
Velocity head
Pressure head + velocity head
Pressure head - velocity head
In a forced vortex, the velocity of flow everywhere within the fluid is
Maximum
Minimum
Zero
Nonzero finite
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
A model of torpedo is tested in a towing tank at a velocity of 25 m/sec. The prototype is expected to attain a velocity of 5 m/sec. What model scale has been used?
1 : 5
1 : 2.5
1 : 25
1 : √5
Bernoulli's equation is applied to
Venturimeter
Orifice meter
Pitot tube
All of these
The discharge through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.
0.34 times
0.67 times
0.81 times
0.95 times
A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?
0.5
0.4
0.515
0.5
The volumetric change of the fluid caused by a resistance is known as
Volumetric strain
Volumetric index
Compressibility
Adhesion