Practice Pakistan's most useful MCQs for competitive exams

In case of bubble cap distillation column of diameter greater than 1.2 metres, the cap diameter is roughly about _______________ cms?

• (A)  10
• (B)  20
• (C)  30
• (D)  35

Answer

Submitted By :Ali Uppal

_____________________ tray arrangement is recommended for distillation column having diameter upto 4 ft ?

• (A)  Radial flow
• (B)  Cross flow
• (C)  Split flow
• (D)  Cascade

Answer

Submitted By :Ali Uppal

In case of a shell and tube heat exchanger, the minimum shell thickness for carbon steel (inclusive of corrosion allowance) depends on shell diameter and is in the range of ________________ mm?

• (A)  3-5
• (B)  5-11
• (C)  8-15
• (D)  12-18

Answer

Submitted By :Ali Uppal

The ratio of shear stress to shear strain is called ____________________?

• (A)  Bulk modulus
• (B)  Shear modulus
• (C)  Modulus of rigidity
• (D)  Modulus of elasticity

Answer

Submitted By :Ali Uppal

A stuffing box is used for____________________?

• (A)  Absorbing the contraction/expansion of pipeline due to temperature changes
• (B)  Prevention of fluid leakage around moving parts
• (C)  Facilitating smooth opening and closing of a valve
• (D)  Reducing the resistance of fluid flow

Answer

Submitted By :Ali Uppal

The ends of a cylindrical vessel can be closed by a head, which can be one of the four shapes. For the same thickness, choose the one which can withstand the highest pressure ?

• (A)  Flat plate
• (B)  Hemispherical
• (C)  Torispherical
• (D)  Ellipsoidal

Answer

Submitted By :Ali Uppal

Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than ______________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop?

• (A)  25
• (B)  50
• (C)  75
• (D)  150

Answer

Submitted By :Ali Uppal

Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger________________?

• (A)  Permits the use of less tubes in a given shell diameter
• (B)  Facilitates comparatively easier external cleaning because of large clearance
• (C)  Permits the use of more tubes in a given shell diameter
• (D)  Both

Answer

Submitted By :Ali Uppal

To keep the power input constant for a stirred vessel operating under fully developed turbulent flow conditions (constant power number), if the impeller diameter is increased by 20%, the impeller speed should be decreased by a factor of_________________?

• (A)  (1.2)3/2
• (B)  (1.2)3/5
• (C)  (1.2)2/3
• (D)  (1.2)5/3

Answer

Submitted By :Ali Uppal

(Le/D) for fully open globe value may be around__________________?

• (A)  10
• (B)  25
• (C)  75
• (D)  300

Answer

Submitted By :Ali Uppal