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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)
- h²
- 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