Hydraulics And Fluid Mechanics Set 3

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This set of Hydraulics and Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Hydraulics And Fluid Mechanics Set 3

Q1 | 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
Q2 | A flow through an expanding tube at constant rate is called
  • Steady uniform flow
  • Steady non-uniform flow
  • Unsteady uniform flow
  • Unsteady non-uniform flow
Q3 | Reynolds number is significant in
  • Supersonics, as with projectile and jet propulsion
  • Full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
  • Simultaneous motion through two fluids where there is a surface of discontinuity, gravity forces, and wave making effect, as with ship's hulls
  • All of the above
Q4 | 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
Q5 | The tendency of a liquid surface to contract is due to the following property
  • Cohesion
  • Adhesion
  • Viscosity
  • Surface tension
Q6 | The Newton's law of resistance is based on the assumption that the
  • Planes of the body are completely smooth
  • Space around the body is completely filled with the fluid
  • Fluid particles do not exert any influence on one another
  • All of the above
Q7 | For manometer, a better liquid combination is one having
  • Higher surface tension
  • Lower surface tension
  • Surface tension is no criterion
  • High density and viscosity
Q8 | 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
Q9 | The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as
  • Meta center
  • Center of pressure
  • Center of buoyancy
  • Center of gravity
Q10 | Stoke is the unit of
  • Kinematic viscosity in C. G. S. units
  • Kinematic viscosity in M. K. S. units
  • Dynamic viscosity in M. K. S. units
  • Dynamic viscosity in S. I. units
Q11 | 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
Q12 | 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
Q13 | Mercury is often used in barometer because
  • It is the best liquid
  • The height of barometer will be less
  • Its vapour pressure is so low that it may be neglected
  • Both (B) and (C)
Q14 | A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?
  • The pressure on the wall at the liquid level is minimum
  • The pressure on the bottom of the wall is maximum
  • The pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum
  • The pressure on the bottom of the wall is zero
Q15 | Center of pressure compared to e.g. is
  • Above it
  • Below it
  • At same point
  • Above or below depending on area of body
Q16 | The centre of gravity of the volume of the liquid displaced by an immersed body is called
  • Centre of gravity
  • Centre of pressure
  • Metacentre
  • Centre of buoyancy
Q17 | Gradually varied flow is
  • Steady uniform
  • Non-steady non-uniform
  • Non-steady uniform
  • Steady non- uniform
Q18 | The viscosity of water at 20°C is
  • One stoke
  • One centistoke
  • One poise
  • One centipoise
Q19 | The velocity of jet of water travelling out of opening in a tank filled with water is proportional to
  • Head of water (h)
  • V/T
  • h/2
Q20 | According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l =Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)
  • flv²/2gd
  • flv²/gd
  • 3flv²/2gd
  • 4flv²/2gd
Q21 | According to Bernoulli's equation for steady ideal fluid flow
  • Principle of conservation of mass holds
  • Velocity and pressure are inversely proportional
  • Total energy is constant throughout
  • The energy is constant along a streamline but may vary across streamlines
Q22 | The discharge through a convergent mouthpiece is __________ the discharge through an internal mouthpiece of the same diameter and head of water.
  • Equal to
  • One-half
  • Three fourth
  • Double
Q23 | Bernoulli equation deals with the law of conservation of
  • Mass
  • Momentum
  • Energy
  • Work
Q24 | Principle of similitude forms the basis of
  • Comparing two identical equipments
  • Designing models so that the result can be converted to prototypes
  • Comparing similarity between design and actual equipment
  • Hydraulic designs
Q25 | The rise of liquid along the walls of a revolving cylinder about the initial level is __________ the depression of the liquid at the axis of rotation.
  • Same as
  • Less than
  • More than
  • None of these