Hydraulics and Fluid Mechanics Questions

• A flow is called sub-sonic, if the Mach number is
• The loss of head at exit of a pipe is
• Which of the following statement is correct?
• The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to
• A flow through an expanding tube at increasing rate is called unsteady non-uniform flow.
• The loss of head at entrance in a pipe is (where v = Velocity of liquid in the pipe)
• In a short cylindrical external mouthpiece, the vena contracta occurs at a distance __________ the diameter of the orifice from the outlet of orifice.
• The discharge through a small rectangular orifice is given by (where Cd = Coefficient of discharge for the orifice, a = Cross-sectional area of the orifice, h = Height of the liquid above the centre of the orifice)
• An open tank containing liquid is moving with an acceleration on an inclined plane. The inclination of the free surface of the liquid will be __________ to the acceleration of the tank.
• The force exerted by a moving fluid on an immersed body is directly proportional to the rate of change of momentum due to the presence of the body. This statement is called
• The flow in a pipe is turbulent when Reynold number is
• The specific weight of sea water is __________ that of pure water.
• According to Pascal's law, the intensity of pressure at any point in a fluid at rest is the same in all directions.
• The intensity of pressure on an immersed surface __________ with the increase in depth.
• In an internal mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to height of the liquid above the vena contracta.
• The flow in a pipe is neither laminar nor turbulent when Reynold number is
• With an increase in size of tube, the rise or depression of liquid in the tube due to surface tension will
• The total energy line lies over the centre line of the pipe by an amount equal to
• The total pressure on a horizontally immersed surface is (where w = Specific weight of the liquid, A = Area of the immersed surface, and x = Depth of the centre of gravity of the immersed surface from the liquid surface)
• The flow in a pipe is laminar, when Reynold number is less than 2000.