Mercury does not wet glass. This is due to property of liquid known as
Adhesion
Cohesion
Surface tension
Viscosity
Correct Answer :
C. Surface tension
Related Questions
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
Hydrometer is used to determine
Specific gravity of liquids
Specific gravity of solids
Specific gravity of gases
Relative humidity
In a short cylindrical external mouthpiece, the vena contracta occurs at a distance __________ the diameter of the orifice from the outlet of orifice.
Equal to
One-fourth
One-third
One-half
When the coefficient of discharge (Cd) is 0.623, then the general equation for discharge over a rectangular weir is
1.84 (L - 0.1nH)H3/2
1.84 (L - nH)H2
1.84 (L - 0.1nH)H5/2
1.84 (L - nH)H3
The Bernoulli's equation is based on the assumption that
There is no loss of energy of the liquid flowing
The velocity of flow is uniform across any cross-section of the pipe
No force except gravity acts on the fluid
All of the above
Select the correct statement
Local atmospheric pressure depends upon elevation of locality only
Standard atmospheric pressure is the mean local atmospheric pressure a* sea level
Local atmospheric pressure is always below standard atmospheric pressure
A barometer reads the difference between local and standard atmospheric pressure
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
According to the principle of buoyancy a body totally or partially immersed in a fluid will be lifted up by a force equal to
The weight of the body
More than the weight of the body
Less than the weight of the body
Weight of the fluid displaced by the body
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
To avoid an interruption in the flow of a siphon, an air vessel is provided
At the inlet
At the outlet
At the summit
At any point between inlet and outlet
For manometer, a better liquid combination is one having
Higher surface tension
Lower surface tension
Surface tension is no criterion
High density and viscosity
For a floating body to be in equilibrium
Meta centre should be above e.g.
Centre of buoyancy and e.g. must lie on same vertical plane
A righting couple should be formed
All of the above
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
The flow in a pipe is neither laminar nor turbulent when Reynold number is
Less than 2000
Between 2000 and 2800
More than 2800
None of these
When the Mach number is less than unity, the flow is called
Sub-sonic flow
Sonic flow
Super-sonic flow
Hyper-sonic flow
The flow in a pipe is turbulent when Reynold number is
Less than 2000
Between 2000 and 2800
More than 2800
None of these
Metacentre is the point of intersection of
Vertical upward force through e.g. of body and center line of body
Buoyant force and the center line of body
Midpoint between e.g. and center of buoyancy
All of the above
Poise is the unit of
Surface tension
Capillarity
Viscosity
Shear stress in fluids
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
The hammer blow in pipes occurs when
There is excessive leakage in the pipe
The pipe bursts under high pressure of fluid
The flow of fluid through the pipe is suddenly brought to rest by closing of the valve
The flow of fluid through the pipe is gradually brought to rest by closing of the valve
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 ratio of absolute viscosity to mass density is known as
Specific viscosity
Viscosity index
Kinematic viscosity
Coefficient of viscosity
A moving fluid mass may be brought to a static equilibrium position, by applying an imaginary inertia force of the same magnitude as that of the accelerating force but in the opposite direction. This statement is called
Pascal's law
Archimedess principle
D-Alembert's principle
None of these
The discharge through a wholly drowned orifice is given by (where H1 = Height of water (on the upstream side) above the top of the orifice, H2 = Height of water (on the downstream side) above the bottom of the orifice, and H = Difference between two water levels on either side of the orifice)
Q = Cd × bH₁ × √(2gh)
Q = Cd × bH2 × √(2gh)
Q = Cd × b (H2 - H1) × √(2gh)
Q = Cd × bH × √(2gh)
Choose the wrong statement
Fluids are capable of flowing
Fluids conform to the shape of the containing vessels
When in equilibrium, fluids cannot sustain tangential forces
When in equilibrium, fluids can sustain shear forces
The specific gravity of water is taken as
0.001
0.01
0.1
1
The weight per unit volume of a liquid at a standard temperature and pressure is called
Specific weight
Mass density
Specific gravity
None of these
The dynamic viscosity of gases __________ with rise in temperature.
Remain unaffected
Increases
Decreases
None of these
According to equation of continuity,
w1a1 = w2a2
w1v1 = w2v2
a1v1 = a2v2
a1/v1 = a2/v2
In one dimensional flow, the flow
Is steady and uniform
Takes place in straight line
Takes place in curve
Takes place in one direction