chemical engineering MCQs – Page 225

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 Review each marked answer and report any item that may be outdated or unclear.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
4481. Pick out the wrong statement ?
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A. Economy of a multiple effect evaporator is not influenced by the boiling point elevation

B. ditions of temperature</strong>

C. Two identical cubes of iron and copper will have the same heat content under the same

D. Finned tube heat exchangers are suitable for heating air by steam

E. Double pipe heat exchangers are mostly used in the field of refrigeration

4482. Boiling point elevation of a solution of NaOH _____________________?
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A. Increases rapidly with temperature rise

B. Is almost independent of temperature

C. Is almost independent of pressure

D. Both B. and C
4483. The Fourier number (defined as a.t/L2) is used in the analysis of problem involving heat transfer by_______________?
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A. Forced convection

B. Steady state conduction

C. Natural convection

D. Transient conduction
4484. Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DV?/?)0.8 (CP.?/k)0.4. This is valid for the value of NRe equal to_______________?
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A. 4000

B. > 10000
4485. For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then__________________?
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A. hf > hd

B. hf = hd

C. hf < hd

D. hf could be greater or smaller than hd

4486. Thermal diffusivity is the most important in heat transfer by__________________?
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A. Conduction

B. Natural convection

C. Radiation

D. Condensation

4487. In physical adsorption, as compared to chemisorption, the________________________?
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A. Heat of adsorption is very large

B. Quantity adsorbed per unit mass is higher

C. Activation energy is very high

D. Rate of adsorption is controlled by the resistance to surface reaction

4488. Lower wall courses of soaking pits are made of _____________ bricks to avoid the action of molten slag & scale?
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A. Low duty fireclay

B. Silicon carbide

C. Silica

D. Chrome or magnesite
4489. Concentration of a solution expressed in terms of _______________ is independent of temperature?
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A. Normality

B. Molarity

C. None of these

D. Molality
4490. Chemically, mullite refractories is________________?
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A. ThO2

B. Al2O3

C. 3Al2O3.2SiO2

D. ZrSO4

4491. Which of the following is concerned with both heat and mass transfer ?
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A. Kutateladze number

B. Lewis relationship

C. Froude number

D. Nusselt number

4492. Quartz is__________________?
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A. All A., B. and C.

B. Converted to Tridymite on firing between 870 to 1470C

C. Stable form of silica upto 870C

D. Transformed to Cristobalite on heating above 1470C

4493. A 2-4 heat exchanger involves__________________?
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A. Only counter-flow of fluids

B. Only parallel-flow of fluids

C. Both counter and parallel-flow of the fluids

D. Smaller pressure drop compared to 1-2 exchanger

4494. For any system, the _____________ heat of solution is dependent on the temperature and the adsorbate concentration?
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A. Integral

B. Differential

C. Both A. & B.

D. Neither A. nor B.

4495. A diathermanous substance _______________ the thermal radiation completely?
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A. Reflects

B. None of these

C. Absorbs

D. Transmits
4496. Fireclay refractories___________________?
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A. All A., B. and C.

B. Combine with salts (e.g. chlorides sulphates etc.) & bases (e.g. lime, magnesia etc.) forming

C. ible aluminates silicates etc

D. Are not resistant to the action of basic slags

E. Shrink during firing

4497. The gravimetric (i.e., by weight) composition of a vapor saturated gas is independent of the_______________?
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A. Nature of both the gas & the liquid

B. Temperature

C. Total pressure

D. None of these
4498. Pick out the wrong statement. In an agitated vertical cylindrical reaction vessel, the___________________?
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A. Filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period

B. Dished bottom vessel has very high power consumption

C. Ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1

D. Flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids

4499. Beryllia (which is used in making crucibles for melting uranium & thorium) is superior to alumina in all respects for high temperature (> 1900C ) use, except______________?
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A. Fusion point

B. Thermal conductivity

C. Electrical conductivity

D. Cost
4500. Baffles are provided in heat exchangers to increase the________________?
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A. Heat transfer area

B. Heat transfer rate

C. Heat transfer co-efficient

D. Fouling factor