A flow is called sub-sonic, if the Mach number is
Less than unity
Unity
Between 1 and 6
More than 6
Correct Answer :
A. Less than unity
Related Questions
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
For hypersonic flow, the Mach number is
Unity
Greater than unity
Greater than 2
Greater than 4
A flow is called sub-sonic, if the Mach number is
Less than unity
Unity
Between 1 and 6
More than 6
Viscous force is the __________ of shear stress due to viscosity and cross-section area of flow.
Sum
Different
Product
Ratio
The discharge over a rectangular notch is
Inversely proportional to H3/2
Directly proportional to H3/2
Inversely proportional to H5/2
Directly proportional to H5/2
Which of the following manometer has highest sensitivity?
U-tube with water
Inclined U-tube
U-tube with mercury
Micro-manometer with water
The horizontal component of buoyant force is
Negligible
Same as buoyant force
Zero
None of the above
An odd shaped body weighing 7.5 kg and occupying 0.01 m3 volume will be completely submerged in a fluid having specific gravity of
1
1.2
0.8
0.75
The atmospheric pressure at sea level is
103 kN/m2
10.3 m of water
760 mm of mercury
All of these
An average value of coefficient of velocity is
0.62
0.76
0.84
0.97
Which of the following is dimensionless?
Specific weight
Specific volume
Specific speed
Specific gravity
A submerged body is said to be in a stable equilibrium, if its centre of gravity __________ the centre of buoyancy.
Coincides with
Lies below
Lies above
None of these
A notch is used to measure __________ of liquids.
Pressure
Discharge
Velocity
Volume
Stoke is the unit of
Kinematic viscosity in C. G. S. units
Kinematic viscosity in M. K. S. units
Dynamic viscosity in M. K. S. units
Dynamic viscosity in S. I. units
The total pressure on a horizontally immersed surface is (where w = Specific weight of the liquid, A = Area of the immersed surface, and x = Depth of the centre of gravity of the immersed surface from the liquid surface)
wA
wx
wAx
wA/x
The shear stress-strain graph for a Newtonian fluid is a
Straight line
Parabolic curve
Hyperbolic curve
Elliptical
The efficiency of power transmission through pipe is (where H = Total supply head, and hf = Head lost due to friction in the pipe)
(H - hf )/H
H/(H - hf )
(H + hf )/H
H/(H + hf )
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 discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.
Less than
More than
Equal to
None of these
To avoid an interruption in the flow of a siphon, an air vessel is provided
At the inlet
At the outlet
At the summit
At any point between inlet and outlet
The coefficient of viscosity may be determined by
Capillary tube method
Orifice type viscometer
Rotating cylinder method
All of these
When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure
Varies as the square of the radial distance
Increases linearly as its radial distance
Increases as the square of the radial distance
Decreases as the square of the radial distance
The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.
Higher
Lower
Same
None of these
Whenever a plate is held immersed at some angle with the direction of flow of the liquid, it is subjected to some pressure. The component of this pressure, in the direction of flow of the liquid, is known as
Lift
Drag
Stagnation pressure
Bulk modulus
The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is
0.0116 stoke
0.116 stoke
0.0611 stoke
0.611 stoke
A nozzle is generally made of
Cylindrical shape
Convergent shape
Divergent shape
Convergent-divergent shape
An ideal flow of any fluid must satisfy
Pascal law
Newton's law of viscosity
Boundary layer theory
Continuity equation
Dynamic viscosity of most of the liquids with rise in temperature
Increases
Decreases
Remain unaffected
Unpredictable
The density of water is 1000 kg/m3 at
0° C
0° K
4° C
20° C
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