Top 350+ Solved Hydraulics and Fluid Mechanics MCQ Questions Answer
Q. The power transmitted through a pipe is (where w = Specific weight in N/m3, and Q = Discharge in m3/s)
a. w × Q × H
b. w × Q × hf
c. w × Q (H - hf)
d. w × Q (H + h )
Q. A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if
a. Length of both the pipes is same
b. Diameter of both the pipes is same
c. Loss of head and discharge of both the pipes is same
d. Loss of head and velocity of flow in both the pipes is same
Q. The center of gravity of the volume of the liquid displaced by an immersed body is called
a. Metacentre
b. Center of pressure
c. Center of buoyancy
d. Center of gravity
Q. A flow is called sub-sonic, if the Mach number is
a. Less than unity
b. Unity
c. Between 1 and 6
d. More than 6
Q. Barometer is used to measure
a. Pressure in pipes, channels etc.
b. Atmospheric pressure
c. Very low pressure
d. Difference of pressure between two points
Q. The center of pressure of a surface subjected to fluid pressure is the point
a. On the surface at which resultant pressure acts
b. On the surface at which gravitational force acts
c. At which all hydraulic forces meet
d. Similar to metacentre
Q. The variation in the volume of a liquid with the variation of pressure is called its
a. Surface tension
b. Compressibility
c. Capillarity
d. Viscosity
Q. The surface tension of mercury at normal temperature is __________ that of water.
a. Same as
b. Lower than
c. Higher than
d. None of these
Q. Flow of water in a pipe about 3 metres in diameter can be measured by
a. Orifice plate
b. Venturimeter
c. Rotameter
d. Pitot tube
Q. According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)
a. (2/3) × Cd (L - nH) ×
b. (2/3) × Cd (L - 0.1nH) × × H3/2
c. (2/3) × Cd (L - nH) × × H²
d. (2/3) × Cd (L - nH) × × H5/2
Q. The equation of continuity holds good when the flow
a. Is steady
b. Is one dimensional
c. Velocity is uniform at all the cross sections
d. All of the above
Q. A thick liquid like syrup has a __________ viscosity than a light liquid like water.
a. Lesser
b. Greater
c. Same
d. None of these
Q. Cavitation will begin when
a. The pressure at any location reaches an absolute pressure equal to the saturated vapour pressure of the liquid
b. Pressure becomes more than critical pressure
c. Flow is increased
d. Pressure is increased
Q. When a liquid is flowing through a pipe, the velocity of the liquid is
a. Maximum at the centre and minimum near the walls
b. Minimum at the centre and maximum near the walls
c. Zero at the centre and maximum near the walls
d. Maximum at the centre and zero near the walls
Q. The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.
a. 0.34 times
b. 0.67 times
c. 0.81 times
d. 0.95 times