The normal stress in a fluid will be constant in all directions at a point only if
It is incompressible
It has uniform viscosity
It has zero viscosity
It is at rest
Correct Answer :
D. It is at rest
Related Questions
If a body floating in a liquid returns back to its original position, when given a small angular displacement, the body is said to be in
Neutral equilibrium
Stable equilibrium
Unstable equilibrium
None of these
The value of mass density in kg-sec-V-m⁴ for water at 0°C is
1
1000
100
101.9
Dimensions of surface tension are
ML°T⁻²
ML°T
ML r²
ML²T²
The error in discharge (dQ/Q) to the error in measurement of head (dH/H) over a triangular notch is given by
dQ/Q = 3/2 × (dH/H)
dQ/Q = 2 × (dH/H)
dQ/Q = 5/2 × (dH/H)
dQ/Q = 3 × (dH/H)
Cavitation is caused by
High velocity
High pressure
Weak material
Low pressure
The vapour pressure over the concave surface is
Less man the vapour pressure over the plane surface
Equal to the vapour pressure over the plane surface
Greater than the vapour pressure over the plane surface
Zero
The units of dynamic or absolute viscosity are
Metres² per sec
kg sec/meter
Newton-sec per meter
Newton-sec² per meter
If no resistance is encountered by displacement, such a substance is known as
Fluid
Water
Gas
Ideal fluid
The pressure of the liquid flowing through the divergent portion of a Venturimeter
Remains constant
Increases
Decreases
Depends upon mass of liquid
Normal depth in open channel flow is the depth of flow corresponding to
Steady flow
Unsteady flow
Laminar flow
Uniform flow
Ratio of inertia force to surface Jension is known as
Mach number
Froude number
Reynoldss number
Weber's number
The resultant upward pressure of the fluid on an immersed body is called
Up-thrust
Buoyancy
Center of pressure
All the above are correct
A jet of water discharging from a 40 mm diameter orifice has a diameter of 32 mm at its vena contracta. The coefficient of contraction is
0.46
0.64
0.78
0.87
The theoretical velocity of jet at vena contracta is (where H = Head of water at vena contracta)
2gH
H × √(2g)
2g × √H
√(2gh)
The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.
Decreases
Increases
Remain same
None of these
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
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
The divergent portion of a Venturimeter is made longer than convergent portion in order to
Avoid the tendency of breaking away the stream of liquid
To minimise frictional losses
Both (A) and (B)
None of these
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 unit of viscosity is
Metres² per sec
kg-sec/metre
Newton-sec per metre²
Newton-sec per meter
The viscosity of a liquid __________ its rate of flow through a hole in a vessel.
Effects
Does not effect
Both A and B
None of these
In the case of steady flow of a fluid, the acceleration of any fluid particle is
Constant
Variable
Zero
Zero under limiting conditions
Metacentric height is the distance between the metacentre and
Water surface
Center of pressure
Center of gravity
Center of buoyancy
An internal mouthpiece is said to be running __________ if the length of the mouthpiece is more than three times the diameter of the orifice.
Free
Partially
Full
None of these
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
A flow through a long pipe at constant rate is called
Steady uniform flow
Steady non-uniform flow
Unsteady uniform flow
Unsteady non-uniform flow
The maximum discharge over a broad crested weir is
0.384 Cd × L × H1/2
0.384 Cd × L × H3/2
1.71 Cd × L × H1/2
1.71 Cd × L × H3/2
The pressure measured with the help of a pressure gauge is called
Atmospheric pressure
Gauge pressure
Absolute pressure
Mean pressure
Gauge pressure at a point is equal to the absolute pressure __________ the atmospheric pressure.
Plus
Minus
Divide
Multiply
An orifice is said to be large, if
The size of orifice is large
The velocity of flow is large
The available head of liquid is more than 5 times the height of orifice
The available head of liquid is less than 5 times the height of orifice