Practice Pakistan's most useful MCQs for competitive exams

Accidents in chemical plants are mostly due to___________________?

• (A)  Inadequate equipment design
• (B)  Faulty operating procedures
• (C)  Improper layout of the equipments
• (D)  Failure of equipments

Answer

Submitted By :Ali Uppal

The equivalent diameter for fluid flow through a channel of constant non-circular cross section of area ‘A’ is given by (where, P = perimeter of the channel in contact with the fluid) ?

• (A)  4 A/P
• (B)  A/P
• (C)  4 P/A
• (D)  √A

Answer

Submitted By :Ali Uppal

The buckling tendency of compression members is always in the direction of the _____________________?

• (A)  Least radius of gyration
• (B)  Axis of the load
• (C)  Perpendicular to the axis of the load
• (D)  None of these

Answer

Submitted By :Ali Uppal

____________ is the determining factor for the number of bubble caps to be used per tray?

• (A)  Permissible slot velocity
• (B)  Tray diameter
• (C)  Liquid load
• (D)  Vapor load

Answer

Submitted By :Ali Uppal

Which of the following is the most common type of baffle used in industrial shell and tube heat exchanger ?

• (A)  75% cut segmental baffle
• (B)  25% cut segmental baffle
• (C)  Orifice baffle
• (D)  Disk and doughnut baffle

Answer

Submitted By :Ali Uppal

The clearance between two tubes in a shell and tube heat exchanger is known as ‘ligament’, whose minimum value is _____________ the outside diameter of the tube, but in no case it should be less than 4.5 mm?

• (A)  Equal to
• (B)  Half
• (C)  One fourth
• (D)  Three fourth

Answer

Submitted By :Ali Uppal

A binary liquid Azeotropic mixture has boiling point lower than either of the components, when it shows _____________ deviation from Raoult’s Law?

• (A)  Positive
• (B)  Negative
• (C)  No
• (D)  None of these

Answer

Submitted By :Ali Uppal

Bubble cap diameter used for the distillation column having diameter ranging from 1.5 to 4.5 metres is about ______________ mm?

• (A)  10
• (B)  50
• (C)  100
• (D)  200

Answer

Submitted By :Ali Uppal

Optimum reflux ratio in a continuous distillation column is determined by the__________________?

• (A)  Maximum permissible vapour velocity
• (B)  Flooding limit of the column
• (C)  Total cost consideration (fixed cost of the column plus the cooling water & steam cost)
• (D)  None of these

Answer

Submitted By :Ali Uppal

In a rotary drier, the average retention time of solid is (where Z = length of the drier, metres ρ = apparent solid density, kg/m3 L = flow rate of dry solids, kg/see. m2 drier crosssection H = hold up of solid.) ?

• (A)  Z.H.ρ/L
• (B)  L/Z.H.ρ
• (C)  H.ρ/L
• (D)  Z.H/ρL

Answer

Submitted By :Ali Uppal