chemical engineering MCQs – Page 183

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 Review each marked answer and report any item that may be outdated or unclear.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
3641. In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5-10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed _______________________ of the column diameter?
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A. 1/5-1/10th

B. 1/10-1/15th

C. 1/20-1/30th

D. 1/2 to 1/4th

3642. Width and depth of grooves in the tube sheet holes normally are _______________ inch respectively?
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A. 1/2 and 8

B. 1/64 and 1/8

C. 1/2 and 5

D. 1/8 and 1/64
3643. In which of the following evaporators, steam is fed inside the tube while the liquor is outside the tube ?
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A. Horizontal tube evaporator

B. Short tube vertical evaporator

C. None of these

D. Long tube vertical evaporator

3644. LMTD correction factor is used in heat exchanger design for____________________?
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A. Multipass shell and tube heat exchanger

B. Fouling fluids

C. Counter flow of hot and cold fluids

D. Double pipe heat exchanger

3645. Compensation against openings in process vessels for giving inlet and outlet connections, for providing sight glasses and manholes etc. is provided for strength and rigidity. The most efficient type of compensation is of _______________ type?
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A. Flared out

B. Ring plate

C. Fluid in

D. Nozzle or rim
3646. Correct use of factor of safety is very important in equipment design. It is defined as the ratio of the___________________?
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A. Ultimate stress to breaking stress

B. Working stress to ultimate stress

C. Ultimate stress to working stress

D. None of these

3647. Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or ______________ times the column diameter, whichever is lower?
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A. 2.5-3.0

B. 10-12.5

C. 15-20

D. 5-7.5

3648. Vertical vessels are not supported by____________________?
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A. Columns

B. Skirts

C. Brackets

D. Saddles
3649. Factor of safety (i.e., overdesign factor) in heat transfer equipments is about _____________ percent more than the actual/theoretical design factor?
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A. 15-20

B. 35-40

C. 30-35

D. 10-May

3650. The ratio of linear stress to linear strain is termed as the ____________________?
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A. None of these

B. Bulk modulus

C. Modulus of rigidity

D. Modulus of elasticity
3651. Baffle width is normally taken as ______________ times the tank diameter?
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A. 0.2-0.45

B. 0.4-0.5

C. 0.45-0.6

D. 0.1-0.12
3652. In a shell and tube heat exchanger, the shortest centre to centre distance between the adjacent tubes is__________________?
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A. Always less than the diameter of the tube

B. Called tube clearance

C. None of these

D. Called tube pitch
3653. 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?
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A. Thermal

B. Tensile

C. Compressive

D. Shear

3654. The equivalent diameter for pressure drop is _______________ that for heat transfer?
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A. Equal to

B. Smaller than

C. Greater than

D. Not related with
3655. Liquid/petroleum fuel storage tanks are built underground (as in case of petrol pumps), when the storage capacity is less than ______________ kilolitres?
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A. 45

B. 30

C. 20

D. 85

3656. In a pressure vessel containing multiple openings of various dimensions at different parts, stress concentration at the edges of the opening is maximum which becomes negligibly small beyond the area covered by ______________ times the hole diameter?
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A. Ten

B. Twenty

C. Five

D. Two
3657. Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is ___________________?
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A. More

B. Less

C. Same

D. Either A. or B.; depends upon the I.D. of the pipe

3658. For turbulent flow (NRe > 2100) of low viscosity fluid (? > 20cp) in steel pipes, the optimum inside pipe diameter is given by(where, Q = fluid flow rate, ft3/sec, ? = fluid density, lb/ft3 ? = fluid viscosity, centipoise Di = optimum inside pipe diameter, inches) ?
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A. Di, opt = 3.9 Q0.45. ?0.95

B. Di, opt = 3 Q0.36. ?0.88

C. Di, opt = 3.9 Q0.45 ?0.13

D. Di, opt = 4.7 Q0.36. ?3.2?0.13

3659. Scale up problem in design based on the similarity concept takes into account _______________ similarity?
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A. Geometrical

B. Kinematic

C. Dynamic

D. All A., B. and C.
3660. Elastic failure of a material occurs, when the tensile stress equals yield strength, yield point or the elastic limit. Also, the elastic failure occurs according to maximum strain theory, when the maximum tensile strain equals (where, ? = yield strength and E = modulus of elasticity) ?
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A. E/?

B. E

C. ?

D. ?/E