As the square of the radius
Inversely as the pressure drop
Inversely as the viscosity
As the square of the diameter
✅ The correct answer is option A.
Fluid Mechanics MCQs
102. Which of the following is the most common pump for pumping either raw sewage or sludge?
Electromagnetic pump
Centrifugal pump
Reciprocating pump
Gear pump
✅ The correct answer is option C.
103. The velocity for subsonic flow in a pipeline
Increases in the downstream direction
Is constant
Decreases in the downstream direction
Is independent of the area of flow
✅ The correct answer is option A.
104. Pressure gradient in the pipe flow is influenced by the
Diameter of pipe
Velocity of the fluid
Density & viscosity of the fluid
All of the above
✅ The correct answer is option D.
105. The length of the tube necessary for the boundary layer to reach the centre of the tube and for fully developed flow to be established is called the __________ length.
Equivalent
Transition
Prandtl mixing
None of these
✅ The correct answer is option B.
106. Which of the following valves will incur maximum pressure drop for the same discharge of water?
Globe valve
Gate valve
Needle valve
Butterfly valve
✅ The correct answer is option C.
107. The pressure co-efficient is the ratio of pressure forces to __________ forces.
Viscous
Inertial
Gravity
Surface tension
✅ The correct answer is option A.
108. For turbulent flow in smooth circular pipe, the velocity distribution is a function of the distance ‘d’ measured from the wall of the pipe and the friction velocity ‘v’, and it follows a __________ relationship.
Logarithmic
Linear
Hyperbolic
Parabolic
✅ The correct answer is option A.
109. Discharge from a 24 inch pipe of water at 10 ft/sec will be __________ ft³/sec.
7.65
32.36
48.22
125.6
✅ The correct answer is option D.
110. Two fluids are flowing through two similar pipes of the same diameter. The Reynold’s number is same. For the same flow rate if the viscosity of a fluid is reduced to half the value of the first fluid, the pressure drop will
Increase
Decrease
Remain unchanged
Data insufficient to predict relative pressure drop
✅ The correct answer is option B.