The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
Half the depth
Half the breadth
Twice the depth
Twice the breadth
Correct Answer :
A. Half the depth
Related Questions
If 850 kg liquid occupies volume of one cubic meter, men 0.85 represents its
Specific weight
Specific mass
Specific gravity
Specific density
The units of kinematic viscosity are
Metres² per sec
kg sec/metre
Newton-sec per metre
Newton-sec per metre
Coefficient of velocity is defined as the ratio of
Actual velocity of jet at vena contracta to the theoretical velocity
Area of jet at vena contracta to the area of orifice
Actual discharge through an orifice to the theoretical discharge
None of the above
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
A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?
0.5
0.4
0.515
0.5
The tendency of a liquid surface to contract is due to the following property
Cohesion
Adhesion
Viscosity
Surface tension
Coefficient of resistance is the ratio of
Actual velocity of jet at vena-contracta to the theoretical velocity
Area of jet at vena-contracta to the area of orifice
Loss of head in the orifice to the head of water available at the exit of the orifice
Actual discharge through an orifice to the theoretical discharge
Water is __________ liquid.
A compressible
An incompressible
Both A and B
None of these
The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.
Higher
Lower
Same
None of these
Surface tension
Acts in the plane of the interface normal to any line in the surface
Is also known as capillarity
Is a function of the curvature of the interface
Decreases with fall in temperature
A flow in which the quantity of liquid flowing per second is constant, is called __________ flow.
Steady
Streamline
Turbulent
Unsteady
An open vessel of water is accelerated up an inclined plane. The free water surface will
Be horizontal
Make an angle in direction of inclination of inclined plane
Make an angle in opposite direction to inclination of inclined plane
Any one of above is possible
Fluid is a substance that
Cannot be subjected to shear forces
Always expands until it fills any container
Has the same shear stress at a point regardless of its motion
Cannot remain at rest under action of any shear force
Buoyant force is
Resultant force acting on a floating body
Equal to the volume of liquid displaced
Force necessary to keep a body in equilibrium
The resultant force on a body due to the fluid surrounding it
Dimensions of surface tension are
ML°T⁻²
ML°T
ML r²
ML²T²
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
One cubic metre of water weighs
100 litres
250 litres
500 litres
1000 litres
A fluid having no viscosity is known as
Real fluid
Ideal fluid
Newtonian fluid
Non-Newtonian fluid
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
In one dimensional flow, the flow
Is steady and uniform
Takes place in straight line
Takes place in curve
Takes place in one direction
A notch is used to measure __________ of liquids.
Pressure
Discharge
Velocity
Volume
Specific weight of water in S.I. units is equal to
1000 N/m3
10000 N/m3
9.81 × 103 N/m3
9.81 × 10⁶ N/m3
Two pipe systems can be said to be equivalent, when the following quantities are same
Friction loss and flow
Length and diameter
Flow and length
Friction factor and diameter
When the Mach number is between __________ the flow is called super-sonic flow.
1 and 2.5
2.5 and 4
4 and 6
1 and 6
Re-entrant or Borda's mouthpiece is an __________ mouthpiece.
Internal
External
Both A and B
None of these
Ratio of inertia force to elastic force is known as
Mach number
Froude number
Reynolds number
Weber's number
Which of the following statement is correct?
In a compressible flow, the volume of the flowing liquid changes during the flow
A flow, in which the volume of the flowing liquid does not change, is called incompressible flow
When the particles rotate about their own axes while flowing, the flow is said to be rotational flow
All of the above
The property by virtue of which a liquid opposes relative motion between its different layers is called
Surface tension
Coefficient of viscosity
Viscosity
Osmosis
For manometer, a better liquid combination is one having
Higher surface tension
Lower surface tension
Surface tension is no criterion
High density and viscosity
Metacentric height is the distance between the metacentre and
Water surface
Center of pressure
Center of gravity
Center of buoyancy