Practice Pakistan's most useful MCQs for competitive exams

Priming is needed in a ______________ pump?

• (A)  Reciprocating
• (B)  Gear
• (C)  Centrifugal
• (D)  Diaphragm

Answer

Submitted By :Ali Uppal

The head developed by a centrifugal pump is largely determined by the____________________?

• (A)  Power of the pump
• (B)  Nature of the liquid being pumped
• (C)  Angle of the vanes and the speed of the tip of the impeller
• (D)  Vapour pressure of the liquid

Answer

Submitted By :Ali Uppal

Applying a pressure drop across a capillary results in a volumetric flow rate ‘Q’ under laminar flow conditions. The flow rate for the same pressure drop, in a capillary of the same length but half the radius is____________________?

• (A)  Q/2
• (B)  Q/4
• (C)  Q/8
• (D)  Q/16

Answer

Submitted By :Ali Uppal

The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost is P. Inlet pressure Q. Compressor rpm R. Delivery pressure S. Volumetric flow rate at inlet ?

• (A)  P, Q and R
• (B)  P and R
• (C)  R and S
• (D)  P, Rand S

Answer

Submitted By :Ali Uppal

Velocity distribution for flow between two fixed parallel plates_________________?

• (A)  Varies parabolically across the section
• (B)  Is constant over the entire cross-section
• (C)  Is zero at the plates and increases linearly to the mid-plane
• (D)  None of these

Answer

Submitted By :Ali Uppal

Upto what value of ‘Mach number’, a fluid may be considered as incompressible ?

• (A)  0.03
• (B)  0.3
• (C)  3
• (D)  10

Answer

Submitted By :Ali Uppal

Where does the maximum stress occur in case of laminar flow of incompressible fluid in a closed conduit of diameter ‘d’ ?

• (A)  At the centre
• (B)  At d/4 from the wall
• (C)  At the wall
• (D)  At d/8 from the wall

Answer

Submitted By :Ali Uppal

The equivalent diameter for flow through a rectangular duct of width B and height H is___________________?

• (A)  HB/2 (H + B)
• (B)  HB/(H + B)
• (C)  2HB/(H + B)
• (D)  4HB/(H + B)

Answer

Submitted By :Ali Uppal

The energy equation, E + (p/ρ) + (V2/2g) + gZ = constant (E = internal energy/mass), is applicable to___________________?

• (A)  Perfect gases only
• (B)  Isothermal flow of gases
• (C)  Adiabatic unsteady flow of gases
• (D)  All compressible fluids

Answer

Submitted By :Ali Uppal

The hydrodynamic and thermal boundary layers will merge, when ____________________?

• (A)  Prandtl number is one
• (B)  Schmidt number tends to infinity
• (C)  Nusselt number tends to infinity
• (D)  Archimedes number is greater than 10000

Answer

Submitted By :Ali Uppal