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This set of Hydraulics and Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on Hydraulics And Fluid Mechanics Set 6

Q1 | The center of pressure of a surface subjected to fluid pressure is the point

- On the surface at which resultant pressure acts
- On the surface at which gravitational force acts
- At which all hydraulic forces meet
- Similar to metacentre

Q2 | The variation in the volume of a liquid with the variation of pressure is called its

- Surface tension
- Compressibility
- Capillarity
- Viscosity

Q3 | The surface tension of mercury at normal temperature is __________ that of water.

- Same as
- Lower than
- Higher than
- None of these

Q4 | Flow of water in a pipe about 3 metres in diameter can be measured by

- Orifice plate
- Venturimeter
- Rotameter
- Pitot tube

Q5 | According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)

- (2/3) × Cd (L - nH) ×
- (2/3) × Cd (L - 0.1nH) × × H3/2
- (2/3) × Cd (L - nH) × × H²
- (2/3) × Cd (L - nH) × × H5/2

Q6 | The equation of continuity holds good when the flow

- Is steady
- Is one dimensional
- Velocity is uniform at all the cross sections
- All of the above

Q7 | A thick liquid like syrup has a __________ viscosity than a light liquid like water.

- Lesser
- Greater
- Same
- None of these

Q8 | Cavitation will begin when

- The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
- Pressure becomes more than critical pressure
- Flow is increased
- Pressure is increased

Q9 | When a liquid is flowing through a pipe, the velocity of the liquid is

- Maximum at the centre and minimum near the walls
- Minimum at the centre and maximum near the walls
- Zero at the centre and maximum near the walls
- Maximum at the centre and zero near the walls

Q10 | The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.

- 0.34 times
- 0.67 times
- 0.81 times
- 0.95 times

Q11 | Resultant pressure of the liquid in the case of an immersed body acts through

- Centre of gravity
- Centre of pressure
- Metacentre
- Centre of buoyancy

Q12 | A fluid is said to be ideal, if it is

- Incompressible
- Viscous and incompressible
- Inviscous and compressible
- Inviscous and incompressible

Q13 | In a depressed nappe

- The pressure below the nappe is atmospheric
- The pressure below the nappe is negative
- The pressure above the nappe is atmospheric
- The pressure above the nappe is negative

Q14 | The value of the coefficient of compressibility for water at ordinary pressure and temperature in kg/cm is equal to

- 2100
- 2700
- 10,000
- 21,000

Q15 | In one dimensional flow, the flow

- Is steady and uniform
- Takes place in straight line
- Takes place in curve
- Takes place in one direction

Q16 | To avoid vaporisation in the pipe line, the pipe line over the ridge is laid such that it is not more than

- 2.4 m above the hydraulic gradient
- 6.4 m above the hydraulic gradient
- 10.0 m above the hydraulic gradient
- 5.0 above the hydraulic gradient

Q17 | The loss of head at exit of a pipe is (where v = Velocity of liquid in the pipe)

- v²/2g
- 0.5v²/2g
- 0.375v²/2g
- 0.75v²/2g

Q18 | Metacentre is the point of intersection of

- Vertical upward force through e.g. of body and center line of body
- Buoyant force and the center line of body
- Midpoint between e.g. and center of buoyancy
- All of the above

Q19 | The imaginary line drawn in the fluid in such a way that the tangent to any point gives thedirection of motion at that point, is known as

- Path line
- Stream line
- Steak line
- Potential line

Q20 | An open vessel of water is accelerated up an inclined plane. The free water surface will

- Be horizontal
- Make an angle in direction of inclination of inclined plane
- Make an angle in opposite direction to inclination of inclined plane
- Any one of above is possible

Q21 | The discharge over a rectangular notch is

- Inversely proportional to H3/2
- Directly proportional to H3/2
- Inversely proportional to H5/2
- Directly proportional to H5/2

Q22 | The flow in which each liquid particle has a definite path and their paths do not cross each other is called

- One dimensional flow
- Streamline flow
- Steady flow
- Turbulent flow

Q23 | The magnitude of water hammer depends upon the

- Elastic properties of the pipe material
- Elastic properties of the liquid flowing through the pipe
- Speed at which the valve is closed
- All of the above

Q24 | The fluid forces considered in the Navier Stokes equation are

- Gravity, pressure and viscous
- Gravity, pressure and turbulent
- Pressure, viscous and turbulent
- Gravity, viscous and turbulent

Q25 | Cavitation is caused by

- High velocity
- High pressure
- Weak material
- Low pressure