Hydraulics Flashcards
Fluid is a substance that
A. cannot be subjected to shear forces
B. always expands until it fills any container
C. has the same shear stress at a point regardless of its motion
D. cannot remain at rest under action of any shear force
D. cannot remain at rest under action of any shear force
Density of water is maximum at
A. 0°C
B. 4°C
C. 100°C
D. 20°C
B. 4°C
Property of a fluid by which its own molecules are attracted is called
A. adhesion
B. cohesion
C. viscosity
D. surface tension
B. cohesion
Property of a fluid by which molecules of
different kinds of fluids are attracted to
each other is called
A. adhesion
B. cohesion
C. viscosity
D. surface tension
A. adhesion
The normal stress in a fluid will be constant in all directions at a point only if
A. it is incompressible
B. it has zero viscosity
C. it is frictionless
D. it is at rest
D. it is at rest
Specific weight of sea water is more that of pure water because it contains
A. dissolved air
B. dissolved salt
C. suspended matter
D. all of the above
D. all of the above
Free surface of a liquid tends to contract to the smallest possible area due to force of
A. surface tension
B. viscosity
C. friction
D. cohesion
A. surface tension
A liquid would wet the solid, if adhesion forces as compared to cohesion forces are
A. less
B. more
C. equal
D. less at low temperature and more
at high temperature
B. more
Barometer is used to measure
A. pressure in pipes, channels etc
B. atmospheric pressure
C. very low pressure
D. difference of pressure between two points
B. atmospheric pressure
Manometer is used to measure
A. pressure in pipes, channels etc.
B. atmospheric pressure
C. very low pressure
D. velocity in pipes
A. pressure in pipes, channels etc.
If cohesion between molecules of a fluid is greater than adhesion between fluid and glass, then the free level of fluid in a dipped glass tube will be
A. higher than the surface of liquid
B. the same as the surface of liquid
C. lower than the surface of liquid
D. unpredictable
C. lower than the surface of liquid
When a fluid is subjected to resistance,
it undergoes a volumetric change due to
A. Cohesion
B. Strain
C. Compressibility
D. Adhesion
C. Compressibility
Liquids transmit pressure equally in all the directions. This is according to
A. Boyle’s law
B. Archimedes principle
C. Pascal’s law
D. Newton’s formula
C. Pascal’s law
The rise or depression of liquid in a tube due to surface tension with an increase in size of tube will
A. increase
B. remain unaffected
C. may increase or decrease depending on the characteristics of liquid
D. decrease
D. decrease
Mercury is often used in barometer because
A. it is the best liquid
B. the height of barometer will be less
C. its vapor pressure is so low that it
may be neglected
D. both (b) and (c)
D. both (b) and (c)
The point in the immersed body through which the resultant pressure of the liquid may be taken to act
is known as
A. metacenter
B. center of pressure
C. center of buoyancy
D. center of gravity
B. center of pressure
Which of the following is the correct relation between centroid (cg) and the center of pressure (cp) of a submerged in a liquid?
A. cg is always below cp
B. cp is always below cg
C. cg is either at cp or below it
D. cp is either at cg or below it
D. cp is either at cg or below it
The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the centroid, if
A. the area is horizontal
B. the area is vertical
C. the area is inclined
D. all of the above
D. all of the above
Choose the wrong statement
A. The horizontal component of the hydro-static force on any surface is equal to the normal force on the vertical projection of the surface
B. The horizontal component acts through the center of pressure for the vertical projection
C. The vertical component of the hydrostatic force on any surface is equal to the weight of the volume of the liquid above the area
D. The vertical component passes through the center of pressure of the volume
D. The vertical component passes through the center of pressure of the volume
Center of pressure on an inclined plane is
A. at the centroid
B. above the centroid
C. below the centroid
D. at metacenter
C. below the centroid
Can center of pressure for a vertical plane submerged surface be ever be above center of gravity?
A. Yes
B. No
C. It can be above in cases where the
surface height is very large
D. None of the mentioned
B. No
In a vertically submerged plane surface, pressure at every point remains same.
A. True
B. False
B. False
For an inclined plate the pressure intensity at every point differs.
A. True
B. False
A. True
The magnitude of total pressure and center of pressure is independent on the shape of the submerged plane surface.
A. True
B. False
B. False
What is the variation of total pressure with depth for any submerged surface if we neglect variation in the density?
A. Linear
B. Parabolic
C. Curvilinear
D. Logarithmic
A. Linear
The resultant upward pressure of a fluid on a floating body is equal to the weight of the fluid displaced by the body. This definition is according to
A. Equilibrium of a floating body
B. Archimedes’ principle
C. Bernoulli’s theorem
D. Metacentric principle
B. Archimedes’ principle
The resultant upward pressure of the fluid on an immersed body is called
A. upthrust
B. buoyant force
C. center of pressure
D. all the above
B. buoyant force
What is the principal cause of action of buoyant force on a body submerged partially or fully in fluid?
A. Displacement of fluid due to submerged body
B. Development of force due to dynamic action
C. Internal shear forces mitigating external forces
D. None of the mentione
A. Displacement of fluid due to
submerged body
The center of gravity of the volume of the liquid displaced by an immersed body is called
A. metacenter
B. center of pressure
C. center of buoyancy
D. center of gravity
C. center of buoyancy