Questions and answers for exam Preparation

MCQs

Total Questions : 1628 | Page 3 of 163 pages

Question 21. 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").

Half
Three fourth
Equal to
1.5 times

Discuss Question

Answer: Option C. -> Equal to

Question 22. Two iron pipes of the same nominal diameter but different schedule numbers will have the same

Inside diameter
Outside diameter
Wall thickness
None of these

Discuss Question

Answer: Option A. -> Inside diameter

Question 23. Le/D for fully open gate valves would be

Much more than that for fully open globe valves
Much less (say 2% than that for fully open globe valves)
Around 7
Both B and C

Discuss Question

Answer: Option D. -> Both B and C

Question 24. Pick out the wrong statement about the design of seive plate column and the bubble cap column.

The downcomer design and the residence time in the downcomer is almost same for seive plate and bubble cap columns
Weir length for a bubble cap plate is the same as that for the seive plate
Weir height for a bubble cap plate column is the same as that for a seive plate column
Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the seive plate

Discuss Question

Answer: Option C. -> Weir height for a bubble cap plate column is the same as that for a seive plate column

Question 25. __________ tray arrangement is recommended for distillation column having diameter upto 4 ft.

Radial flow
Cross flow
Split flow
Cascade

Discuss Question

Answer: Option B. -> Cross flow

Question 26. Hole diameter of the seive trays in the distillation column ranges from __________ mm.

L to 3
4 to 8
3 to 12.5
12.5 to 18.5

Discuss Question

Answer: Option C. -> 3 to 12.5

Question 27. With increase in the reflux ratio for a fixed production from a continuous binary distillation column, the __________ decreases.

Fixed charges initially
Running cost of cooling water for condenser
Vapour & liquid load both
Running cost of steam for reboiler

Discuss Question

Answer: Option A. -> Fixed charges initially

Question 28. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones ; because the smaller diameter tubes

Are easier to clean
Are less prone to fouling
Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
None of these

Discuss Question

Answer: Option C. -> Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less

Question 29. Liquid gradient over a tray can be minimised by

Providing a higher skirt clearance or a higher weir
Decreasing the number of rows of caps through which the liquid flows or by decreasing the velocity of liquid flow past the caps or by reducing the distance along the tray through which the liquid must
Using split flow, radial flow or cascade flow for column diameter large than 4 ft
All of the above

Discuss Question

Answer: Option D. -> All of the above

Question 30. Needle valves are generally not used for