Top 350+ Solved Hydraulics and Fluid Mechanics MCQ Questions Answer
Q. When a body is placed over a liquid, it will sink down if
a. Gravitational force is equal to the up-thrust of the liquid
b. Gravitational force is less than the up-thrust of the liquid
c. Gravitational force is more than the up-thrust of the liquid
d. None of the above
Q. The property by virtue of which a liquid opposes relative motion between its different layers iscalled
a. Surface tension
b. Coefficient of viscosity
c. Viscosity
d. Osmosis
Q. A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ halfthe height of water above the weir crest.
a. Equal to
b. Less than
c. More than
d. None of these
Q. Euler's dimensionless number relates the following
a. Inertial force and gravity
b. Viscous force and inertial force
c. Viscous force and buoyancy force
d. Pressure force and inertial force
Q. When a body floating in a liquid, is displaced slightly, it oscillates about
a. C.G. of body
b. Center of pressure
c. Center of buoyancy
d. Metacentre
Q. When the Mach number is between __________ the flow is called super-sonic flow.
a. 1 and 2.5
b. 2.5 and 4
c. 4 and 6
d. 1 and 6
Q. In an immersed body, centre of pressure is
a. At the centre of gravity
b. Above the centre of gravity
c. Below be centre of gravity
d. Could be above or below e.g. depending on density of body and liquid
Q. Steady flow occurs when
a. The direction and magnitude of the velocity at all points are identical
b. The velocity of successive fluid particles, at any point, is the same at successive periods of time
c. The magnitude and direction of the velocity do not change from point to point in the fluid
d. The fluid particles move in plane or parallel planes and the streamline patterns are identical in each plane
Q. A flow is called super-sonic if the
a. Velocity of flow is very high
b. Discharge is difficult to measure
c. Mach number is between 1 and 6
d. None of these
Q. In a forced vortex, the velocity of flow everywhere within the fluid is
a. Maximum
b. Minimum
c. Zero
d. Nonzero finite
Q. Mach number is significant in
a. Supersonics, as with projectiles and jet propulsion
b. Full immersion or completely enclosed flow, as with pipes, aircraft wings, nozzles etc.
c. Simultaneous motion through two fluids where there is a surface of discontinuity, gravity force, and wave making effects, as with ship's hulls
d. All of the above
Q. In order that flow takes place between two points in a pipeline, the differential pressure betweenthese points must be more than
a. Frictional force
b. Viscosity
c. Surface friction
d. All of the above
Q. The error in discharge (dQ/Q) to the error in measurement of head (dH/H) over a triangular notch is given by
a. dQ/Q = 3/2 × (dH/H)
b. dQ/Q = 2 × (dH/H)
c. dQ/Q = 5/2 × (dH/H)
d. dQ/Q = 3 × (dH/H)
Q. For similarity, in addition to models being geometrically similar to prototype, the following in both cases should also be equal
a. Ratio of inertial force to force due to viscosity
b. Ratio of inertial force to force due to gravitation
c. Ratio of inertial force to force due to surface tension
d. All the four ratios of inertial force to force due to viscosity, gravitation, surface tension, and elasticity
Q. The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.
a. Decreases
b. Increases
c. Remain same
d. None of these