Top 350+ Solved Hydraulics and Fluid Mechanics MCQ Questions Answer
Q. A streamline is defined as the line
a. Parallel to central axis flow
b. Parallel to outer surface of pipe
c. Of equal velocity in a flow
d. Along which the pressure drop is uniform
Q. The flow in a pipe or channel is said to be non-uniform when
a. The liquid particles at all sections have the same velocities
b. The liquid particles at different sections have different velocities
c. The quantity of liquid flowing per second is constant
d. Each liquid particle has a definite path
Q. Hydrometer is used to determine
a. Specific gravity of liquids
b. Specific gravity of solids
c. Specific gravity of gases
d. Relative humidity
Q. The dynamic viscosity of the liquid __________ with rise in temperature.
a. Remain unaffected
b. Increases
c. Decreases
d. None of these
Q. For pipes, turbulent flow occurs when Reynolds number is
a. Less than 2000
b. Between 2000 and 4000
c. More than 4000
d. Less than 4000
Q. The velocity of the liquid flowing through the divergent portion of a Venturimeter
a. Remains constant
b. Increases
c. Decreases
d. Depends upon mass of liquid
Q. The volumetric change of the fluid caused by a resistance is known as
a. Volumetric strain
b. Volumetric index
c. Compressibility
d. Adhesion
Q. If the depth of water in an open channel is less than the critical depth, the flow is called
a. Critical flow
b. Turbulent flow
c. Tranquil flow
d. Torrential flow
Q. An orifice is said to be large, if
a. The size of orifice is large
b. The velocity of flow is large
c. The available head of liquid is more than 5 times the height of orifice
d. The available head of liquid is less than 5 times the height of orifice
Q. A piece of metal of specific gravity 13.6 is placed in mercury of specific gravity 13.6, what fraction of it volume is under mercury?
a. The metal piece will simply float over the mercury
b. The metal piece will be immersed in mercury by half
c. Whole of the metal piece will be immersed with its top surface just at mercury level
d. Metal piece will sink to the bottom
Q. The centre of pressure acts __________ the centre of gravity of immersed surface.
a. At
b. Above
c. Below
d. None of these
Q. Dynamic viscosity of most of the liquids with rise in temperature
a. Increases
b. Decreases
c. Remain unaffected
d. Unpredictable
Q. The discharge over a right angled notch is (where H = Height of liquid above the apex of notch)
a. (8/15) Cd. 2g. H
b. (8/15) Cd. 2g. H3/2
c. (8/15) Cd. 2g. H²
d. (8/15) C 2g. H5/2
Q. A square surface 3 m × 3 m lies in a vertical line in water pipe its upper edge at water surface. The hydrostatic force on square surface is
a. 9,000 kg
b. 13,500 kg
c. 18,000 kg
d. 27,000 kg
Q. Select the correct statement
a. Local atmospheric pressure depends upon elevation of locality only
b. Standard atmospheric pressure is the mean local atmospheric pressure a* sea level
c. Local atmospheric pressure is always below standard atmospheric pressure
d. A barometer reads the difference between local and standard atmospheric pressure