At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be
Minimum
Maximum
Zero
Could be any value
Correct Answer :
D. Could be any value
Related Questions
A water tank contains 1.3 m deep water. The pressure exerted by the water per metre length of the tank is
2.89 kN
8.29 kN
9.28 kN
28.9 kN
The bulk modulus of elasticity
Has the dimensions of 1/pressure
Increases with pressure
Is large when fluid is more compressible
Is independent of pressure and viscosity
A piece of wood having weight 5 kg floats in water with 60% of its volume under the liquid. The specific gravity of wood is
0.83
0.6
0.4
0.3
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
The total pressure on the surface of a vertical sluice gate 2 m x 1 m with its top 2 m surface being 0.5 m below the water level will be
500 kg
1000 kg
1500 kg
2000 kg
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
Bulk modulus of a fluid is the ratio of
Shear stress to shear strain
Increase in volume to the viscosity of fluid
Increase in pressure to the volumetric strain
Critical velocity to the viscosity of fluid
Select the wrong statement
An equivalent pipe is treated as an ordinary pipe for all calculations
The length of an equivalent pipe is equal to that of a compound pipe
The discharge through an equivalent pipe is equal to that of a compound pipe
The diameter of an equivalent pipe is equal to that of a compound pipe
The flow in which the velocity vector is identical in magnitude and direction at every point, for any given instant, is known as
One dimensional flow
Uniform flow
Steady flow
Turbulent flow
The pressure in the air space above an oil (sp. gr. 0.8) surface in a tank is 0.1 kg/cm. The pressure at 2.5 m below the oil surface will be
2 metres of water column
3 metres of water column
3.5 metres of water column
4 m of water column
A flow in which the quantity of liquid flowing per second is constant, is called __________ flow.
Steady
Streamline
Turbulent
Unsteady
An average value of coefficient of velocity is
0.62
0.76
0.84
0.97
In a lock-gate, the reaction between two gates is (where P = Resultant pressure on the lock gate, and α = Inclination of the gate with the normal to the side of the lock)
p/sinα
2p/sinα
p/2sinα
2p/sin (α/2)
The ratio of the inertia force to the elastic force is called
Reynold's number
Froude's number
Weber's number
Mach number
A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific gravity is
1
5
7
6
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
For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal
Ratio of inertial force to force due to viscosity
Ratio of inertial force to force due to gravitation
Ratio of inertial force to force due to surface tension
All the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity
An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called
Weir
Notch
Orifice
None of these
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
In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be
Running full
Running free
Partially running full
Partially running free
The rise of liquid along the walls of a revolving cylinder about the initial level is __________ the depression of the liquid at the axis of rotation.
Same as
Less than
More than
None of these
The property of a liquid which offers resistance to the movement of one layer of liquid over another adjacent layer of liquid, is called
Surface tension
Compressibility
Capillarity
Viscosity
Newton's law of viscosity is a relationship between
Pressure, velocity and temperature
Shear stress and rate of shear strain
Shear stress and velocity
Rate of shear strain and temperature
A square surface 3 m × 3 m lies in a vertical line in water pipe its upper edge at water surface. The hydrostatic force on square surface is
9,000 kg
13,500 kg
18,000 kg
27,000 kg
If the depth of water in an open channel is less than the critical depth, the flow is called
Critical flow
Turbulent flow
Tranquil flow
Torrential flow
Mercury does not wet glass. This is due to property of liquid known as
Adhesion
Cohesion
Surface tension
Viscosity
The product of mass and acceleration of flowing liquid is called
Inertia force
Viscous force
Gravity force
Pressure force
Flow of water in a pipe about 3 metres in diameter can be measured by
Orifice plate
Venturimeter
Rotameter
Pitot tube
The centre of gravity of the volume of the liquid displaced by an immersed body is called
Centre of gravity
Centre of pressure
Metacentre
Centre of buoyancy
When an internal mouthpiece is running free, the discharge through the mouthpiece is: (where a = Area of mouthpiece, and H = Height of liquid above the mouthpiece)
0.5 a. √2gH
0.707 a. √2gH
0.855 a. √2gH
a. √2gH