### Hydraulics And Fluid Mechanics Set 6

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 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
• 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
• 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