Practice Pakistan's most useful MCQs for competitive exams

The location of centre of pressure, which defines the point of application of the total pressure force on the surface, can be calculated by applying the principle of moments according to which “sum of the moment of the resultant force about an axis is equal to the sum of the components about the same axis”. The centre of pressure of a rectangular surface (of width ‘w’) immersed vertically in a static mass of fluid is at a depth of (where, y = depth of the liquid) ?

• (A)  1/(y/3)
• (B)  2y/3
• (C)  1/(y/4)
• (D)  3y/4

Answer

Submitted By :Ali Uppal

In a free vortex, the_____________________?

• (A)  Velocity changes linearly with radial distance
• (B)  Flow is necessarily rotational
• (C)  Radial component of velocity is same everywhere
• (D)  Stream lines are not circular

Answer

Submitted By :Ali Uppal

For laminar flow of a fluid through a packed bed of spheres of diameter d, the pressure drop per unit length of bed depends upon the sphere diameter as_________________?

• (A)  d
• (B)  d2
• (C)  d4
• (D)  d̅ 2

Answer

Submitted By :Ali Uppal

Which is the most efficient and best for measuring very small flow rate of gases ?

• (A)  Venturimeter
• (B)  Orificemeter
• (C)  Rotameter
• (D)  Flow nozzle

Answer

Submitted By :Ali Uppal

Newton’s law of viscosity relates the____________________?

• (A)  Shear stress and velocity
• (B)  Velocity gradient and pressure intensity
• (C)  Shear stress and rate of angular deformation in a fluid
• (D)  Pressure gradient and rate of angular deformation

Answer

Submitted By :Ali Uppal

Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will _____________ the gas discharge pressure?

• (A)  Increase
• (B)  Decrease
• (C)  Not change
• (D)  Exponentially decrease

Answer

Submitted By :Ali Uppal

Bernoulli’s equation is not applicable, when the flow is___________________?

• (A)  Irrotational
• (B)  Incompressible
• (C)  Viscous
• (D)  All

Answer

Submitted By :Ali Uppal

The fluid velocity varies as the square root of the cylindrical pipe diameter in case of steady state laminar flow at constant pressure drop of _____________ fluid?

• (A)  Dilatent
• (B)  Pseudo-plastic
• (C)  Bingham plastic
• (D)  Newtonian

Answer

Submitted By :Ali Uppal

In a/an _____________, the flow rate of fluids is obtained by measuring the difference between the impact and the static pressure?

• (A)  Rotameter
• (B)  Pitot tube
• (C)  Venturimeter
• (D)  Flow nozzle

Answer

Submitted By :Ali Uppal

_____________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2?

• (A)  Centrifugal
• (B)  Piston
• (C)  Plunger
• (D)  Vane

Answer

Submitted By :Ali Uppal