The ratio of the inertia force to the viscous force is called
Reynold's number
Froude's number
Weber's number
Euler's number
Correct Answer :
A. Reynold's number
Related Questions
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
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
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 buoyancy depends on
Mass of liquid displaced
Viscosity of the liquid
Pressure of the liquid displaced
Depth of immersion
The normal stress is same in all directions at a point in a fluid
Only when the fluid is frictionless
Only when the fluid is incompressible and has zero viscosity
When there is no motion of one fluid layer relative to an adjacent layer
Irrespective of the motion of one fluid layer relative to an adjacent layer
The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream
Keeps on increasing
Keeps on decreasing
Remain constant
May increase/decrease
The top of the weir over which the water flows is known as
Sill or crest
Nappe or vein
Orifice
None 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
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
Working principle of dead weight pressure gauge tester is based on
Pascal's law
Dalton's law of partial pressure
Newton's law of viscosity
Avogadro's hypothesis
The force of buoyancy is always __________ the weight of the liquid displaced by the body.
Equal to
Less than
More than
None of these
According to Bazin's formula, the discharge over a rectangular weir is mL2g x H3/2where m is equal to
0.405 + (0.003/H)
0.003 + (0.405/H)
0.405 + (H/0.003)
0.003 + (H/0.405)
A vessel of 4 m3 contains oil which weighs 30 kN. The specific weight of the oil is
4.5 kN/m3
6 kN/m3
7.5 kN/m3
10 kN/m3
A streamline is defined as the line
Parallel to central axis flow
Parallel to outer surface of pipe
Of equal velocity in a flow
Along which the pressure drop is uniform
A body floating in a liquid is said to be in neutral equilibrium, if its metacentre
Coincides with its centre of gravity
Lies above its centre of gravity
Lies below its centre of gravity
Lies between the centre of buoyancy and centre of gravity
A nozzle placed at the end of a water pipe line discharges water at a
Low pressure
High pressure
Low velocity
High velocity
Falling drops of water become spheres due to the property of
Surface tension of water
Compressibility of water
Capillarity of water
Viscosity of water
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
Two dimensional flows occurs when
The direction and magnitude of the velocity at all points are identical
The velocity of successive fluid particles, at any point, is the same at successive periods of time
The magnitude and direction of the velocity do not change from point to point in the fluid
The fluid particles move in plane or parallel planes and the streamline patterns are identical in each plane
The coefficient of viscosity may be determined by
Capillary tube method
Orifice type viscometer
Rotating cylinder method
All of these
During the opening of a valve in a pipe line, the flow is
Steady
Unsteady
Uniform
Laminar
A manometer is used to measure
Atmospheric pressure
Pressure in pipes and channels
Pressure in Venturimeter
Difference of pressures between two points in a pipe
The fluid forces considered in the Navier Stokes equation are
Gravity, pressure and viscous
Gravity, pressure and turbulent
Pressure, viscous and turbulent
Gravity, viscous and turbulent
The discharge over a rectangular notch is (where b = Width of notch, and H = Height of liquid, above the sill of the notch)
(2/3) Cd × b × √(2gH)
(2/3) Cd × b × √(2g) × H
(2/3) Cd × b × √(2g) × H3/2
(2/3) Cd × b × √(2g) × H2
The coefficient of discharge for an external mouthpiece depends upon
Velocity of liquid
Pressure of liquid
Area of mouthpiece
Length of mouthpiece
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
The meatcentric height is the distance between the
Centre of gravity of the floating body and the centre of buoyancy
Centre of gravity of the floating body and the metacentre
Metacentre and centre of buoyancy
Original centre of buoyancy and new centre of buoyancy
The two important forces for a floating body are
Buoyancy, gravity
Buoyancy, pressure
Buoyancy, inertial
Inertial, gravity
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
The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called
Density of liquid
Specific gravity of liquid
Compressibility of liquid
Surface tension of liquid