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)
Correct Answer :
A. 1/2 × depth
Related Questions
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
Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called
Adhesion
Cohesion
Viscosity
Compressibility
Bernoulli equation deals with the law of conservation of
Mass
Momentum
Energy
Work
The dynamic viscosity of the liquid __________ with rise in temperature.
Remain unaffected
Increases
Decreases
None of these
The ratio of the inertia force to the viscous force is called
Reynold's number
Froude's number
Weber's number
Euler's number
The pressure intensity in kN/m2 (or kPa) at any point in a liquid is (where w = Specific weight of liquid, and h = Depth of liquid from the surface)
w
wh
w/h
h/w
Choose the wrong statement
The horizontal component of the hydrostatic force on any surface is equal to the normal force on the vertical projection of the surface
The horizontal component acts through the center of pressure for the vertical projection
The vertical component of the hydrostatic force on any surface is equal to the weight of the volume of the liquid above the area
The vertical component passes through the center of pressure of the volume
Mercury does not wet glass. This is due to property of liquid known as
Adhesion
Cohesion
Surface tension
Viscosity
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
Unit of surface tension is
Energy/unit area
Velocity/unit area
Both of the above
It has no units
When a body is placed over a liquid, it will float if
Gravitational force is equal to the up-thrust of the liquid
Gravitational force is less than the up-thrust of the liquid
Gravitational force is more than the up-thrust of the liquid
None of the above
Choose the wrong statement
Viscosity of a fluid is that property which determines the amount of its resistance to a shearing force
Viscosity is due primarily to interaction between fluid molecules
Viscosity of liquids decreases with increase in temperature
Viscosity of liquids is appreciably affected by change in pressure
Poise is the unit of
Surface tension
Capillarity
Viscosity
Shear stress in fluids
Capillary action is due to the
Surface tension
Cohesion of the liquid
Adhesion of the liquid molecules and the molecules on the surface of a solid
All of the above
The water pressure per metre length on a vertical masonry wall of dam is (where w = Specific weight of the liquid, and H = Height of the liquid)
wH/2
wH
wH2/2
wH2/4
The pressure of fluid due to hammer blow is
Directly proportional to density of fluid
Inversely proportional to density of fluid
Directly proportional to (density)1/2 of fluid
Inversely proportional to (density)1/2 of fluid
In order to avoid tendency of separation at throat in a Venturimeter, the ratio of the diameter at throat to the diameter of pipe should be
1/16 to 1/8
1/8 to 1/4
1/4 to 1/3
1/3 to 1/2
A glass tube of smaller diameter is used while performing an experiment for the capillary rise of water because
It is easier to see through the glass tube
Glass tube is cheaper than a metallic tube
It is not possible to conduct this experiment with any other tube
All of the above
A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if
Length of both the pipes is same
Diameter of both the pipes is same
Loss of head and discharge of both the pipes is same
Loss of head and velocity of flow in both the pipes is same
A pitot tube is used to measure the
Velocity of flow at the required point in a pipe
Pressure difference between two points in a pipe
Total pressure of liquid flowing in a pipe
Discharge through a pipe
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
One litre of water occupies a volume of
100 cm3
250 cm3
500 cm3
1000 cm3
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
In a forced vortex, the velocity of flow everywhere within the fluid is
Maximum
Minimum
Zero
Nonzero finite
The total energy line lies over the centre line of the pipe by an amount equal to
Pressure head
Velocity head
Pressure head + velocity head
Pressure head - velocity head
The unit of dynamic viscosity in S.I. units is
N-m/s2
N-s/m2
Poise
Stoke
Which of the following meters is not associated with viscosity?
Red wood
Say bolt
Engler
Orsat
The units of kinematic viscosity are
Metres² per sec
kg sec/metre
Newton-sec per metre
Newton-sec per metre
The height of a water column equivalent to a pressure of 0.15 MPa is
15.3 m
25.3 m
35.3 m
45.3 m
The conditions for the stable equilibrium of a floating body are
The metacentre should lie above the center of gravity
The center of buoyancy and the center of gravity must lie on the same vertical line
A righting couple should be formed
All the above are correct