chemical engineering MCQs – Page 179

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
3561. In case of saddle packing (e.g., berl and intralox saddles), the maximum size of the packing should not exceed ______________ of the column diameter?
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A. 1/15th

B. 1/50th

C. 1/5th

D. 1/30th

3562. Cooling water fouling factors vary in the range of 0.001 to 0.003____________________?
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A. (W/m2.K)-1

B. (BTU/hr.ft2. F)-1

C. (kcal/hr. m. C)-1

D. (kcal/hr.m2.C)-1

3563. A stuffing box is used for____________________?
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A. Prevention of fluid leakage around moving parts

B. Reducing the resistance of fluid flow

C. Absorbing the contraction/expansion of pipeline due to temperature changes

D. Facilitating smooth opening and closing of a valve

3564. Optimum reflux ratio in a continuous distillation column is determined by the__________________?
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A. Total cost consideration (fixed cost of the column plus the cooling water & steam cost)

B. Maximum permissible vapour velocity

C. Flooding limit of the column

D. None of these

3565. (Le/D) for fully open globe value may be around__________________?
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A. 25

B. 10

C. 300

D. 75

3566. The testing pressure of storage tanks and pressure vessels designed as per Indian standard codes should be about ______________ times the design pressure?
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A. 3 to 4

B. 1.5 to 2

C. 4 to 5

D. > 5

3567. Poissons ratio of a material is the ratio of unit lateral strain to the unit axial elongation within its elastic limit. The value of Poissons ratio for structural and pressure vessel steel may be taken as ____________________?
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A. 0.01

B. 0.3

C. 0.95

D. 0.75

3568. The minimum tray spacing in distillation column of diameter less than 3 ft is normally _____________ inches?
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A. 18

B. 34

C. 24

D. 6
3569. 25 per cent cut segmental baffle means that the baffle__________________?
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A. Height is 75% of the I.D. of the shell

B. Width is 25% of its height

C. Height is 25% of the I.D. of the shell

D. Spacing is 75% of its height

3570. In case of design of a shell and tube heat exchanger___________________?
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A. All A., B. & C.

B. mm tube diameter; and for > 15 mm tube diameter, tube sheet thickness is smaller than

C. O.D. of the tube is 6 to 40 mm while the tube lengths used are 0.5, 2.5, 3.0, 4.0, 5.0, 6 metres

D. Minimum tube sheet thickness (in which tubes are fixed) is equal to the O.D. of the tube upto

E. Minimum cleaning lane of 6.5 mm is provided, when tubes are on a square pitch

F. e diameter

3571. In hydrostatic testing of welded pipe (for leakage, strength etc.) the ratio of minimum hydrostatic test pressure to internal design pressure is around __________________?
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A. 1.5

B. 3.5

C. 0.5

D. 2.5

3572. An under-designed steam trap will___________________?
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A. Waste steam

B. Back up condensate and cause water hammer in steam line

C. Destroy itself of acceleration wear due to rapid recycling

D. None of these

3573. Circumferential (hoop) stress in a thin cylindrical vessel under internal pressure is _____________ the longitudinal stress?
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A. Eight times

B. Twice

C. Equal to

D. Half

3574. Most of the storage vessels/tanks are made cylindrical, because of the fact that a cylinder _________________?
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A. Has greater structural strength

B. Is easy to fabricate

C. Both A. and B.

D. Neither A. nor B.

3575. In a shell and tube heat exchanger, the clearance of the tube is generally___________________?
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A. Equal to the tube diameter

B. More in case of triangular pitch as compared to the square pitch tube layout

C. More than the tube diameter

D. Not less than one-fourth of the tube diameter or 3/16?
3576. In a _____________ riveted joint, the number of rivets decreases from the innermost row to the outermost row?
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A. Zig-zag

B. Diamond

C. None of these

D. Chain

3577. The ratio of tube length to shell diameter in case of liquid shell and tube heat exchanger ranges from__________________?
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A. 4 to 8

B. 6 to 12

C. 3 to 5

D. 2 to 3

3578. _____________ shaped roof is the most commonly used roof for cylindrical storage tanks?
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A. Conical

B. Dome

C. Umbrella

D. Flat

3579. Value of Peclet number = 0, is the representative of ____________________?
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A. Eddy diffusivity = 0

B. Laminar flow

C. Complete back mixing

D. Plug flow

3580. Accidents in chemical plants are mostly due to___________________?
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A. Improper layout of the equipments

B. Failure of equipments

C. Faulty operating procedures

D. Inadequate equipment design