### Hydraulics And Fluid Mechanics Set 1

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
• 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
• 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