The highest efficiency is obtained with a channel of __________ section.
Circular
Square
Rectangular
Trapezoidal
Correct Answer :
D. Trapezoidal
Related Questions
The hydraulic mean depth for a circular pipe of diameter (d) is
d/6
d/4
d/2
d
Which of the following is dimensionless?
Specific weight
Specific volume
Specific speed
Specific gravity
The discharge over a rectangular weir, considering the velocity of approach, is (whereH1 = H + Ha = Total height of water above the weir, H = Height of water over the crest of the weir, and Ha = Height of water due to velocity of approach)
(2/3) Cd × L.√2g [H1 - Ha]
(2/3) Cd × L. √2g [H1 3/2 - Ha 3/2]
(2/3) Cd × L.√2g [H1 2 - Ha 2]
(2/3) Cd × L. √2g [H1 5/2 - Ha 5/2]
The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is
Directly proportional to (radius)2
Inversely proportional to (radius)2
Directly proportional to (radius)4
Inversely proportional to (radius)4
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 purpose of a surge tank is
To control the pressure variations due to rapid changes in the pipe line flow
To eliminate water hammer possibilities
To regulate flow of water to turbines by providing necessary retarding head of water
All of the above
For a perfect incompressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another. This statement is called
Continuity equation
Bernoulli's equation
Pascal's law
Archimedess principle
The difference of pressure between the inside and outside of a liquid drop is
p = T × r
p = T/r
p = T/2r
p = 2T/r
Falling drops of water become spheres due to the property of
Surface tension of water
Compressibility of water
Capillarity of water
Viscosity of water
When the flow in an open channel is gradually varied, the flow is said to be
Steady uniform flow
Steady non-uniform flow
Unsteady uniform flow
Unsteady non-uniform flow
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
If w is the specific weight of liquid and k the depth of any point from the surface, then pressure intensity at that point will be
h
wh
w/h
h/w
The discharge through a channel of trapezoidal section is maximum when
Width of channel at the top is equal to twice the width at the bottom
Depth of channel is equal to the width at the bottom
The sloping side is equal to half the width at the top
The sloping side is equal to the width at the bottom
The ratio of the inertia force to the __________ is called Euler's number.
Pressure force
Elastic force
Surface tension force
Viscous force
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
The most economical section of a trapezoidal channel is one which has hydraulic mean depth equal to
1/2 × depth
1/2 × breadth
1/2 × sloping side
1/4 × (depth + breadth)
One cubic metre of water weighs
100 litres
250 litres
500 litres
1000 litres
In order to measure the flow with a Venturimeter, it is installed in
Horizontal line
Inclined line with flow upwards
Inclined line with flow downwards
Any direction and in any location
In an external mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to 0.89 times the height of the liquid, above the vena contracta.
Less than
More than
Equal to
None of these
A structure, whose width is __________ the width of the channel, is called a flumed structure.
Less than
More than
Equal
None of these
The specific weight of water in S.I. units is taken as
9.81 kN/m3
9.81 × 103 N/m3
9.81 × 10-6 N/mm3
Any one of these
The mass per unit volume of a liquid at a standard temperature and pressure is called
Specific weight
Mass density
Specific gravity
None of these
In a free nappe,
The pressure below the nappe is atmospheric
The pressure below the nappe is negative
The pressure above the nappe is atmospheric
The pressure above the nappe is negative
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
Bernoulli's equation is applied to
Venturimeter
Orifice meter
Pitot tube
All of these
Metacentric height is the distance between the metacentre and
Water surface
Center of pressure
Center of gravity
Center of buoyancy
The factional resistance of a pipe varies approximately with __________ of the liquid.
Pressure
Velocity
Square of velocity
Cube of velocity
When a body is immersed wholly or partially in a liquid, it is lifted up by a force equal to the weight of liquid displaced by the body. This statement is called
Pascal's law
Archimedess principle
Principle of floatation
Bernoulli's theorem
The length of a liquid stream while flowing over a weir __________ at the ends of the sill.
Expands
Does not change
Contracts
None of these
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