Hydraulics And Fluid Mechanics Set 1

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This set of Hydraulics and Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Hydraulics And Fluid Mechanics Set 1

Q1 | When a body is placed over a liquid, it will sink down if
  • Gravitational force is equal to the up-thrust of the liquid
  • Gravitational force is less than the up-thrust of the liquid
  • Gravitational force is more than the up-thrust of the liquid
  • None of the above
Q2 | The property by virtue of which a liquid opposes relative motion between its different layers iscalled
  • Surface tension
  • Coefficient of viscosity
  • Viscosity
  • Osmosis
Q3 | A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ halfthe height of water above the weir crest.
  • Equal to
  • Less than
  • More than
  • None of these
Q4 | Euler's dimensionless number relates the following
  • Inertial force and gravity
  • Viscous force and inertial force
  • Viscous force and buoyancy force
  • Pressure force and inertial force
Q5 | When a body floating in a liquid, is displaced slightly, it oscillates about
  • C.G. of body
  • Center of pressure
  • Center of buoyancy
  • Metacentre
Q6 | When the Mach number is between __________ the flow is called super-sonic flow.
  • 1 and 2.5
  • 2.5 and 4
  • 4 and 6
  • 1 and 6
Q7 | In an immersed body, centre of pressure is
  • At the centre of gravity
  • Above the centre of gravity
  • Below be centre of gravity
  • Could be above or below e.g. depending on density of body and liquid
Q8 | Steady flow occurs when
  • The direction and magnitude of the velocity at all points are identical
  • The velocity of successive fluid particles, at any point, is the same at successive periods of time
  • The magnitude and direction of the velocity do not change from point to point in the fluid
  • The fluid particles move in plane or parallel planes and the streamline patterns are identical in each plane
Q9 | A flow is called super-sonic if the
  • Velocity of flow is very high
  • Discharge is difficult to measure
  • Mach number is between 1 and 6
  • None of these
Q10 | In a forced vortex, the velocity of flow everywhere within the fluid is
  • Maximum
  • Minimum
  • Zero
  • Nonzero finite
Q11 | Mach number is significant in
  • Supersonics, as with projectiles 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 force, and wave making effects, as with ship's hulls
  • All of the above
Q12 | In order that flow takes place between two points in a pipeline, the differential pressure betweenthese points must be more than
  • Frictional force
  • Viscosity
  • Surface friction
  • All of the above
Q13 | The error in discharge (dQ/Q) to the error in measurement of head (dH/H) over a triangular notch is given by
  • dQ/Q = 3/2 × (dH/H)
  • dQ/Q = 2 × (dH/H)
  • dQ/Q = 5/2 × (dH/H)
  • dQ/Q = 3 × (dH/H)
Q14 | For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal
  • Ratio of inertial force to force due to viscosity
  • Ratio of inertial force to force due to gravitation
  • Ratio of inertial force to force due to surface tension
  • All the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity
Q15 | The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.
  • Decreases
  • Increases
  • Remain same
  • None of these
Q16 | 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
  • Higher than the surface of liquid
  • The same as the surface of liquid
  • Lower than the surface of liquid
  • Unpredictable
Q17 | The ratio of the inertia force to the __________ is called Euler's number.
  • Pressure force
  • Elastic force
  • Surface tension force
  • Viscous force
Q18 | A one dimensional flow is one which
  • Is uniform flow
  • Is steady uniform flow
  • Takes place in straight lines
  • Involves zero transverse component of flow
Q19 | According to Manning's formula, the discharge through an open channel is (where M = Manning's constant)
  • A × M × m1/2 × i2/3
  • A × M × m2/3 × i1/2
  • A1/2 × M 2/3 × m × i
  • A2/3 × M1/3 × m × i
Q20 | An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called
  • Weir
  • Notch
  • Orifice
  • None of these
Q21 | The property of fluid by virtue of which it offers resistance to shear is called
  • Surface tension
  • Adhesion
  • Cohesion
  • Viscosity
Q22 | Coefficient of velocity is defined as the ratio of
  • Actual velocity of jet at vena contracta to the theoretical velocity
  • Area of jet at vena contracta to the area of orifice
  • Actual discharge through an orifice to the theoretical discharge
  • None of the above
Q23 | The mass of 2.5 m3 of a certain liquid is 2 tonnes. Its mass density is
  • 200 kg/m3
  • 400 kg/m3
  • 600 kg/m3
  • 800 kg/m3
Q24 | A fluid in equilibrium can't sustain
  • Tensile stress
  • Compressive stress
  • Shear stress
  • Bending stress
Q25 | When a plate is immersed in a liquid parallel to the flow, it will be subjected to a pressure __________ that if the same plate is immersed perpendicular to the flow.
  • Less than
  • More than
  • Equal to
  • None of these