chemical engineering MCQs – Page 222

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 Review each marked answer and report any item that may be outdated or unclear.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

4421. 1000 Kg of liquid at 30C in a well stirred vessel has to be heated to 120C, using immersed coils carrying condensing steam at 150C. The area of the steam coils is 1.2 m2 and the overall heat transfer co-efficient to the liquid is 1500 W/m2.C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.C, the time taken for the liquid to reach desired temperature will be__________________?
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A. 15 min

B. 51 min

C. 44 min

D. 22 min

4422. Pick out the wrong unit conversion of thermal conductivity ?
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A. 1 BTU/ft2.hr.F/inch = 1.488 kcal/m2. hr.C/m

B. 1 kcal/m.hr.C = 0.672 BTU/ft.hr.F = 1.163 W/m. K

C. 1 BTU/ft2.hr.F/ft = 1.488 kcal/m2. hr.C/m

D. 1 W/cm.C = 85.985 kcal/m.hr.C = 57.779 BTU/ft.hr.F

4423. Kirchoff?s law applies to _____________ radiation?
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A. Total

B. Monochromatic

C. Both A. & B.

D. Neither A. nor B.

4424. Fireclay bricks are not used in the_________________?
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A. Blast furnace

B. Hot blast stove

C. Wall of coke oven

D. Cupola

4425. Pick out the wrong statement?
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A. The tensile strength of a brittle material is less than its compressive strength

B. The compressive strength of a ductile material is less than its tensile strength

C. The value of crushing load is more than that of buckling load for long columns

D. In a thick cylindrical shell, the hoop stress is maximum at the inner radius

4426. Pick out the wrong statement?
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A. Superduty fireclay bricks correspond to a pyrometric cone equivalent of 26-28

B. Graphite refractories are also called plumbago refractories

C. Insulating refractories used in place of regular refractory bricks are usually called light weight refractories, and they have similar composition as heavy bricks

D. Calcined magnesite is also called dead burnt magnesite

4427. 1 BTU/lb.?F is equivalent to ____________ kcal/kg.C?
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A. 1.987

B. 4.97

C. 1

D. 2.42

4428. Weight of 56 litres of ammonia at N.T.P. is _____________ gm?
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A. 56

B. 42.5

C. 2.5

D. 2800

4429. _____________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side?
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A. Single pass, fixed tube sheet

B. None of these

C. U-tube

D. Three pass, fixed tube sheet

4430. Prandtl and Reynolds analogy are same, when Prandtl number is____________________?
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A. 1.5

B. > 2

C. 0.5

D. 1

4431. Dry air is a mixture of__________________?
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A. Vapors

B. Gases

C. Both A. & B.

D. Neither A. nor B.

4432. Pick out the wrong statement?
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A. The heat capacity of a heterogeneous mixture is an additive property, but when solutions are formed, this additive property may no longer exist

B. Generally, the heat capacities of compounds are lower in the liquid than in the solid state

C. Atomic heat capacities of all solid elements decrease greatly with decrease in temperature, approaching a value of zero at absolute zero temperature, when in the crystalline state

D. Atomic heat capacities of the crystalline solid elements are nearly constant and equal to 6.2 kcal/kg-atom according to the law of Petit and Dulong

4433. Pick out the wrong unit conversion of temperature?
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A. F = (C + 17.778) 1.8

B. R = 273 + F

C. C = (F- 32) 0.555

D. Temperature difference of 1K = 1C = 9/5F

4434. Thermal conductivities of most of the liquids _______________ with rise in temperature?
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A. May increase or decrease; depends on the liquid

B. Remains unchanged

C. Increases

D. Decreases

4435. Carborundum used for making crucibles for melting non-ferrous metals is chemically________________?
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A. Silicon nitride