Practice Pakistan's most useful MCQs for competitive exams

In case of a shell and tube heat exchanger, the effect of L/D on inside film heat transfer coefficient (hi) vanishes after a Reynold number of_____________?

• (A)  1000
• (B)  3000
• (C)  5000
• (D)  10000

Answer

Submitted By :Ali Uppal

The safe distance of habitation from a hazardous chemical plant (TLV of its product < 1000 ppm) should be about ______________ kms?

• (A)  1
• (B)  5
• (C)  15
• (D)  25

Answer

Submitted By :Ali Uppal

Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about _____________ kcal/hr.m2.°C?

• (A)  1250
• (B)  2500
• (C)  7500
• (D)  15000

Answer

Submitted By :Ali Uppal

Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than ______________ kilolitres?

• (A)  20
• (B)  30
• (C)  45
• (D)  85

Answer

Submitted By :Ali Uppal

Reflux ratio variation in a distillation column is between___________________?

• (A)  Zero and infinity
• (B)  Zero and one
• (C)  Minimum and infinity
• (D)  None of these

Answer

Submitted By :Ali Uppal

The type of stress developed in a metallic bar on subjecting it to a change in temperature without allowing it to be deformed is ______________ stress?

• (A)  Shear
• (B)  Tensile
• (C)  Compressive
• (D)  Thermal

Answer

Submitted By :Ali Uppal

In a continuous distillation column, the optimum reflux ratio ranges from _______________ times the minimum reflux ratio?

• (A)  1.1 to 1.5
• (B)  1.6 to 2
• (C)  2.2 to 2.6
• (D)  2.7 to 3

Answer

Submitted By :Ali Uppal

Speed of the drum of the rotary vacuum filter normally ranges from _____________ rpm?

• (A)  0.1 to 2
• (B)  5 to 7
• (C)  3 to 8
• (D)  8 to 15

Answer

Submitted By :Ali Uppal

For a cylindrical vessel of moderate height, the weld joint efficiency for joints parallel to the cylindrical axis is given as 1.0; while for joints along the girth (circumference) it is given as 0.8. In calculating the shell wall thickness using code formula for an internally pressurised cylindrical vessel, what value of weld joint efficiency should be used ?

• (A)  0.8
• (B)  0.9
• (C)  1.0
• (D)  (0.8)0.5

Answer

Submitted By :Ali Uppal

25 per cent cut segmental baffle means that the baffle__________________?

• (A)  Height is 75% of the I.D. of the shell
• (B)  Height is 25% of the I.D. of the shell
• (C)  Spacing is 75% of its height
• (D)  Width is 25% of its height

Answer

Submitted By :Ali Uppal