Practice Pakistan's most useful MCQs for competitive exams

Tubes are fixed to the tube sheet (a thick circular metallic plate) by the method of tube rolling and brazing (non-removable) or ferrule connection (removable). Thickness of the tube, sheet is normally ____________ the outside diameter of the tube but in no case it should be less than 22 mm (7/8″)?

• (A)  Half
• (B)  Three fourth
• (C)  Equal to
• (D)  1.5 times

Answer

Submitted By :Ali Uppal

Maximum plate efficiency is achieved in case of ______________ flow?

• (A)  Split
• (B)  Cross
• (C)  Cascade
• (D)  Reverse

Answer

Submitted By :Ali Uppal

Le/D) for 90° elbow (medium radius) and 90°square elbow would be respectively around___________________?

• (A)  25 and 60
• (B)  3 and 5
• (C)  100 and 250
• (D)  250 and 600

Answer

Submitted By :Ali Uppal

Diameter of the sieve tray column is determined by the_________________?

• (A)  Lower limit of vapour velocity
• (B)  Upper limit of the vapour velocity
• (C)  Hole diameter of the sieve tray
• (D)  Height of the plate spacing

Answer

Submitted By :Ali Uppal

Maximum acceptable total liquid gradient over a tray is about _______________ mm?

• (A)  5.5
• (B)  12.5
• (C)  30.5
• (D)  45.5

Answer

Submitted By :Ali Uppal

Normal screwed fittings are used for pipes upto a diameter of _______________ inches?

• (A)  1.5
• (B)  3
• (C)  5
• (D)  9

Answer

Submitted By :Ali Uppal

The ratio of lateral strain to linear strain is termed as the___________________?

• (A)  Poisson’s ratio
• (B)  Bulk modulus
• (C)  Modulus of elasticity
• (D)  Shear modulus

Answer

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Angled baffles are preferred in the agitation tank to control the swirling action; if the viscosity of the liquid to be mixed is about 200 poise. However, the baffle may be completely eliminated for mixing liquids having viscosity above ____________________ poise?

• (A)  300
• (B)  600
• (C)  1000
• (D)  1500

Answer

Submitted By :Ali Uppal

Which of the following efficiencies can be greater than 100% ?

• (A)  Overall plate efficiency
• (B)  Murphree plate efficiency
• (C)  Point efficiency
• (D)  None of these

Answer

Submitted By :Ali Uppal

Minimum tube pitch recommended for shell and tube heat exchangers is about _______________ times the outside diameter of the tube?

• (A)  1.25
• (B)  1.75
• (C)  2.5
• (D)  3.5

Answer

Submitted By :Ali Uppal