Free Fluid Flow Operations MCQs with Answers

• A. Gravity
• B. Drag
• C. Buoyant
• D. All A., B., & C.

Explanation: A particle moving through a stationary fluid experiences its weight, buoyant force from displaced fluid, and drag opposing relative…

• A. h1 > h2 < h3
• B. h1 > h2 > h3
• C. h2 < h1 < h3
• D. h1 < h2 < h3

Explanation: In a venturi, velocity is greatest at the throat, so the pressure or piezometric head there is lowest.

• A. H3/2
• B. H5/2
• C. H1/2
• D. H2/3

Explanation: Integrating the elemental discharge across a V-notch gives Q proportional to H^(5/2).

• A. Sluggish
• B. Spouted
• C. Boiling
• D. Teeter

Explanation: Large particles such as grains are difficult to suspend uniformly by ordinary fluidisation and are commonly handled in a spouted bed…

• A. Irrotational flow only
• B. Ideal/non i viscous fluids only
• C. Cases of axial symmetry
• D. None of these

Explanation: The Stokes stream function is formulated for axisymmetric flow, where the three-dimensional flow can be represented using a…

• A. None of these
• B. Cool the delivered air
• C. Achieve the exact delivery pressure
• D. Save power in compressing a given volume to a given pressure

Explanation: Interstage cooling lowers the temperature and specific volume of the gas before the next compression stage, reducing the work required for…

• A. Torque applied
• B. Force exerted
• C. Work done
• D. Power developed

Explanation: The angular-momentum equation states that the rate of change of moment of momentum equals the torque applied to the fluid.

• A. Reciprocating
• B. Gear
• C. Diaphragm
• D. Multistage centrifugal

Explanation: Boiler feed water must be delivered at high pressure, so multistage centrifugal pumps are commonly used because several impellers provide…

• A. Froude
• B. Mach
• C. Euler
• D. Weber

Explanation: The Froude number compares inertial force with gravitational force, commonly written as Fr = v divided by the square root of gL.

• A. For non-symmetrical bodies is not vertical
• B. Depends on the weight of the floating body
• C. Depends on the depth of the submergence of the floating body
• D. None of these

Explanation: For a floating body, equilibrium requires the buoyant force to equal the body's weight, so the buoyant force depends on that weight.

• A. Opened
• B. Either opened or closed; it does not make any difference
• C. Closed
• D. Either opened or closed; depending on the fluid viscosity

Explanation: A centrifugal pump is started with its delivery valve closed because this minimizes the starting flow and the power required by the motor.

• A. Mass
• B. Energy
• C. Both A. & B.
• D. Momentum

Explanation: The Navier-Stokes equation is Newton's second law applied to a fluid element, expressing conservation of momentum.

• A. Notch
• B. Hot wire anemometer
• C. Rotameter
• D. Segmental orifice

Explanation: A notch, especially a V-notch, measures open-channel flow from the upstream liquid head, using a calibrated head-discharge relationship.

• A. V-notch
• B. Pitot tube
• C. Rotameter
• D. All A., B. and C.

Explanation: A rotameter is a variable-area flowmeter: the float moves until the opening area changes enough to balance the flow forces.

• A. Froude number
• B. None of these
• C. Pressure co-efficient
• D. Kinematic viscosity

Explanation: Kinematic viscosity has dimensions of area divided by time, or L²/T, so it is dimensional.

• A. Displaced volume of the fluid
• B. Submerged body
• C. Volume of fluid vertically above the body
• D. Horizontal projection of the body

Explanation: The buoyant force acts through the centre of buoyancy, which is the centre of gravity or centroid of the displaced fluid volume.

• A. High density
• B. Very low vapor pressure
• C. Low capillary action
• D. Low compressibility

Explanation: Mercury has very low vapour pressure, so its vapour contributes negligibly to the pressure reading in a barometer.

• A. Store a definite quantity of water all the time
• B. Facilitate easy dismantling of pipeline for cleaning and maintenance
• C. Reduce the water hammer
• D. None of these

Explanation: A surge tank absorbs sudden changes in flow and pressure when the water velocity changes, thereby reducing water hammer in a high-pressure…

• A. Hyperbolic
• B. None of these
• C. Linear
• D. Parabolic

Explanation: For fully developed laminar flow between parallel plates, the velocity profile is parabolic because the pressure-gradient force is…

• A. Decreases
• B. Increases
• C. Remain constant
• D. May increase or decrease; depends on the liquid

Explanation: Heating a liquid generally weakens the cohesive forces between its molecules, so its resistance to flow decreases.