The shear stress-strain graph for a Newtonian fluid is a
Straight line
Parabolic curve
Hyperbolic curve
Elliptical
Correct Answer :
A. Straight line
Related Questions
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
When a tube of smaller diameter is dipped in water, the water rises in the tube with an upward __________ surface.
Concave
Convex
Plane
None of these
A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.
Equal to
Less than
More than
None of these
Poise is the unit of
Surface tension
Capillarity
Viscosity
Shear stress in fluids
Choose the correct relationship
Specific gravity = gravity × density
Dynamic viscosity = kinematic viscosity × density
Gravity = specific gravity × density
Kinematic viscosity = dynamic viscosity × density
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
A large Reynold number is indication of
Smooth and streamline flow
Laminar flow
Steady flow
Highly turbulent flow
Cavitation will begin when
The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
Pressure becomes more than critical pressure
Flow is increased
Pressure is increased
The property of a fluid which enables it to resist tensile stress is known as
Compressibility
Surface tension
Cohesion
Adhesion
Piezometer is used to measure
Pressure in pipe, channels etc.
Atmospheric pressure
Very low pressures
Difference of pressure between two points
Property of a fluid by which molecules of different kinds of fluids are attracted to each other is called
Adhesion
Cohesion
Viscosity
Compressibility
When a cylindrical vessel of radius (r) containing liquid is revolved about its vertical axis ω rad/s, then depth of parabola which the liquid assumes is
ω.r/2g
ω².r²/2g
ω.r/4g
ω².r²/4g
A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?
The metal piece will simply float over the mercury
The metal piece will be immersed in mercury by half
Whole of the metal piece will be immersed with its top surface just at mercury level
Metal piece will sink to the bottom
A water tank contains 1.3 m deep water. The pressure exerted by the water per metre length of the tank is
2.89 kN
8.29 kN
9.28 kN
28.9 kN
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
The power transmitted through the nozzle is maximum when the head lost due to friction in the pipe is __________ of the total supply head.
One-half
One-third
Two-third
None of these
A piece weighing 3 kg in air was found to weigh 2.5 kg when submerged in water. Its specific gravity is
1
5
7
6
The discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.
Less than
More than
Equal to
None of these
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)
The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the
Pressure head
Velocity head
Pressure head + velocity head
Pressure head - velocity head
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
Dynamic viscosity of most of the liquids with rise in temperature
Increases
Decreases
Remain unaffected
Unpredictable
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
Buoyant force is
The resultant force acting on a floating body
The resultant force on a body due to the fluid surrounding it
Equal to the volume of liquid displaced
The force necessary to maintain equilibrium of a submerged body
The point at which the resultant pressure on an immersed surface acts, is known as
Centre of gravity
Centre of depth
Centre of pressure
Centre of immersed surface
A flow whose streamline is represented by a curve, is called
One-dimensional flow
Two-dimensional flow
Three-dimensional flow
Four-dimensional flow
The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number)
1/RN
4/RN
16/RN
64/RN
A flow in which each liquid particle has a definite path, and the paths of individual particles do not cross each other, is called
Steady flow
Uniform flow
Streamline flow
Turbulent flow
The center of gravity of the volume of the liquid displaced by an immersed body is called
Metacentre
Center of pressure
Center of buoyancy
Center of gravity
The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the submerged body is called
Up-thrust
Reaction
Buoyancy
Metacentre