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This set of Hydraulics and Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Hydraulics And Fluid Mechanics Set 12

Q1 | A uniform body 3 m long, 2 m wide and 1 m deep floats in water. If the depth of immersion is 0.6m, then the weight of the body is

- 3.53 kN
- 33.3 kN
- 35.3 kN
- None of these

Q2 | The force per unit length is the unit of

- Surface tension
- Compressibility
- Capillarity
- Viscosity

Q3 | When the Mach number is more than 6, the flow is called

- Sub-sonic flow
- Sonic flow
- Super -sonic flow
- Hyper-sonic flow

Q4 | The upper surface of a weir over which water flows is known is

- Crest
- Nappy
- Sill
- Weir top

Q5 | One cubic metre of water weighs

- 100 litres
- 250 litres
- 500 litres
- 1000 litres

Q6 | Kinematic viscosity is dependent upon

- Pressure
- Distance
- Density
- Flow

Q7 | The discharge through a large rectangular orifice is given by (where H1 = Height of the liquid above the top of the orifice, H2 = Height of the liquid above the bottom of the orifice, b = Breadth of the orifice, and Cd = Coefficient of discharge)

- Q = (2/3) Cd × b × (2g) × (H2 - H1)
- Q = (2/3) Cd × b × (2g) × (H2 1/2- H1 1/2)
- Q = (2/3) Cd × b × (2g) × (H2 3/2 - H1 3/2)
- Q = (2/3) Cd × b × (2g) × (H2 2 - H1 2)

Q8 | An error of 1% in measuring head over the apex of the notch (H) will produce an error of _________ in discharge over a triangular notch.

- 1%
- 1.50%
- 2%
- 2.50%

Q9 | The Euler's equation for the motion of liquids is based upon the assumption that

- The fluid is non - viscous, homogeneous and incompressible
- The velocity of flow is uniform over the section
- The flow is continuous, steady and along the stream line
- All of the above

Q10 | The ratio of the inertia force to the viscous force is called

- Reynold's number
- Froude's number
- Weber's number
- Euler's number

Q11 | The total energy of a liquid particle in motion is equal to

- Pressure energy + kinetic energy + potential energy
- Pressure energy - (kinetic energy + potential energy)
- Potential energy - (pressure energy + kinetic energy
- Kinetic energy - (pressure energy + potential energy)

Q12 | Which of the following instrument can be used for measuring speed of a submarine moving in deep sea?

- Venturimeter
- Orifice plate
- Hot wire anemometer
- Pitot tube

Q13 | The force present in a moving liquid is

- Inertia force
- Viscous force
- Gravity force
- All of these

Q14 | A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water?

- 10 m/sec
- 25 m/sec
- 2 m/sec
- 50 m/sec

Q15 | The flow in which the velocity vector is identical in magnitude and direction at every point, for anygiven instant, is known as

- One dimensional flow
- Uniform flow
- Steady flow
- Turbulent flow

Q16 | The coefficient of discharge for an external mouthpiece depends upon

- Velocity of liquid
- Pressure of liquid
- Area of mouthpiece
- Length of mouthpiece

Q17 | The specific weight of water is 1000 kg/m3

- At normal pressure of 760 mm
- At 4°C temperature
- At mean sea level
- All the above

Q18 | If the depth of water in an open channel is greater than the critical depth, the flow is called

- Critical flow
- Turbulent flow
- Tranquil flow
- Torrential flow

Q19 | When a cylindrical vessel, containing some liquid, is rotated about its vertical axis, the liquid surface is depressed down at the axis of its rotation and rises up near the walls of the vessel on all sides. This type of flow is known as

- Steady flow
- Turbulent flow
- Vortex flow
- Uniform flow

Q20 | The body will sink down if the force of buoyancy is __________ the weight of the liquid displaced.

- Equal to
- Less than
- More than
- None of these

Q21 | The total pressure on the surface of a vertical sluice gate 2 m x 1 m with its top 2 m surface being 0.5 m below the water level will be

- 500 kg
- 1000 kg
- 1500 kg
- 2000 kg

Q22 | The velocity at which the laminar flow stops, is known as

- Velocity of approach
- Lower critical velocity
- Higher critical velocity
- None of these

Q23 | The line of action of the buoyant force acts through the

- Centroid of the volume of fluid vertically above the body
- Centre of the volume of floating body
- Center of gravity of any submerged body
- Centroid of the displaced volume of fluid

Q24 | The buoyancy depends upon the

- Weight of the liquid displaced
- Pressure with which the liquid is displaced
- Viscosity of the liquid
- Compressibility of the liquid

Q25 | Two dimensional flows 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