**621. Which of the following produces maximum pressure difference for transportation of gases ?**

A. Vacuum pumps

B. Blowers

C. Fans**D. Compressors**

**622. Pressure difference between two points in vessels, pipelines or in two different pipelines can be measured by a differential manometer. The pressure difference measured as the mm of water column in case of mercury-water, differential manometer is equal to (where, H = difference in height of mercury column in mm)?**

A. H**B. 12.6 H**

C. 13.6 H

D. 14.6 H

**623. The head loss in turbulent flow in a pipe varies_________________?**

A. Directly as the velocity

B. Inversely as the square of the velocity**C. Approximately as the square of the velocity**

D. Inversely as the square of the diameter

**624. Navier-Stokes equation is useful in the analysis of _____________ fluid flow problems?**

A. Non-viscous**B. Viscous**

C. Turbulent

D. Rotational

**625. A pipe has a porous section of length L as shown in the figure. Velocity at the start of this section of V0. If fluid leaks into the pipe through the porous section at a volumetric rate per unit area q(x/L)2, what will be axial velocity in the pipe at any „x‟? Assume incompressible one dimensional flow i.e., no gradients in the radial direction ?**

A. VX = V0 + q (x3/L2D)

B. VX = V0 + ⅓q (x3/L2)

C. VX = V0 + 2q (x2/LD)**D. VX = V0 + (4/3) q (x3/L2D)**

**626. A fluid which has a linear relationship between the magnitude of applied shear-stress and the resulting rate of deformation is called a/an _____________ fluid?****A. Newtonian**

B. Non-Newtonian

C. Ideal

D. Incompressible

**627. Venturimeter and orificemeter measures the _____________ of the fluid?**

A. Pressure

B. Maximum velocity**C. Average velocity**

D. Point velocity

**628. Which of the following valves will incur maximum pressure drop for the same discharge of water ?**

A. Globe valve

B. Gate valve**C. Needle valve**

D. Butterfly valve

**629. At low Reynolds number______________?**

A. Viscous forces are unimportant

B. Viscous forces control**C. Viscous forces control and inertial forces are unimportant**

D. Gravity forces control

**630. Transition from laminar flow to turbulent flow is aided by the__________________?**

A. Surface roughness and curvature (i.e. sharp corners)

B. Vibration

C. Pressure gradient and the compressibility of the flowing medium**D. All A., B. & C.**

**NOTEIF YOU THINK ANY OF THE MCQ ABOVE IS WRONG.PLEASE COMMENT WITH CORRECT ANSWER AND ITS DETAIL EXPLANATION IN COMMENT BOX.THANK YOU**