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MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1651. |
Under conditions of flooding in packed tower, the gas pressure drop |
| A. | decreases rapidly |
| B. | increases rapidly |
| C. | remains constant |
| D. | is maximum |
| Answer» E. | |
| 1652. |
Positive deviation from Raoult's law means a mixture whose total pressure is |
| A. | greater than that computed for ideality. |
| B. | less than that computed for ideality. |
| C. | less than the sum of the vapour pressure of the components. |
| D. | none of these. |
| Answer» B. less than that computed for ideality. | |
| 1653. |
Very tall packed towers are divided into series of beds to |
| A. | reduce the overall pressure drop |
| B. | avoid channelling |
| C. | reduce liquid hold-up |
| D. | avoid flooding |
| Answer» C. reduce liquid hold-up | |
| 1654. |
Moisture contained by a substance in excess of the equilibrium moisture is called the __________ moisture. |
| A. | unbound |
| B. | free |
| C. | critical |
| D. | bound |
| Answer» C. critical | |
| 1655. |
With increase in temperature, the solubility of gases in liquids, at fixed pressure |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | either (a) or (b), depends on the system |
| Answer» C. remains same | |
| 1656. |
In most of the vacuum crystalliser, vacuum is generally produced by means of a |
| A. | suction pump |
| B. | compressed air jet |
| C. | steam jet ejector with a barometric condenser |
| D. | none of these |
| Answer» D. none of these | |
| 1657. |
Which of the following binary systems is an example of a maximum boiling azeotrope ? |
| A. | Water-hydrochloric acid. |
| B. | Acetone-carbon disulphide. |
| C. | Water-ethyl alcohol. |
| D. | n-heptane-n-octane. |
| Answer» B. Acetone-carbon disulphide. | |
| 1658. |
(NRe . NSc) is termed in mass transfer operation as the __________ number. |
| A. | Stanton |
| B. | Sherwood |
| C. | Peclet |
| D. | none of these |
| Answer» D. none of these | |
| 1659. |
The value of Lewis number (Le = Sc/Pr) for air-water vapour system is around |
| A. | 1 |
| B. | 0.24 |
| C. | 3.97 |
| D. | 600 |
| Answer» B. 0.24 | |
| 1660. |
Molarity is defined as the number of gm moles of solute per __________ of solvent. |
| A. | litre |
| B. | kg |
| C. | gm |
| D. | c.c |
| Answer» B. kg | |
| 1661. |
Which of the following T-H diagram is valid for dehumidification operation ? |
| A. | <img src="/_files/images/chemical-engineering/mass-transfer/317-501-1.png"> |
| B. | <img src="/_files/images/chemical-engineering/mass-transfer/317-501-2.png"> |
| C. | <img src="/_files/images/chemical-engineering/mass-transfer/317-501-3.png"> |
| D. | <img src="/_files/images/chemical-engineering/mass-transfer/317-501-4.png"> |
| Answer» B. <img src="/_files/images/chemical-engineering/mass-transfer/317-501-2.png"> | |
| 1662. |
An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii) |
| A. | less number of trays are required. |
| B. | composition of the residue remains unchanged. |
| C. | more number of trays are required but the residue composition remains unchanged. |
| D. | more number of trays are required and the residue composition is more dilute in methanol. |
| Answer» B. composition of the residue remains unchanged. | |
| 1663. |
The partial pressure distribution of an ideal gas diffusing through another stagnant ideal gas at steady state follows a/an __________ law. |
| A. | exponential |
| B. | parabolic |
| C. | linear |
| D. | cubic |
| Answer» B. parabolic | |
| 1664. |
Corresponding to Nusselt number in heat transfer, the dimensionless group in mass transfer is the __________ number. |
| A. | Sherwood |
| B. | Schmidt |
| C. | Peclet |
| D. | Stanton |
| Answer» B. Schmidt | |
| 1665. |
If the specific heats of a gas and a vapor are 0.2KJ/Kg. K and 1.5 KJ/Kg. K respectively, and the humidity is 0.01; the humid heat in KJ/ Kg. is |
| A. | 0.31 |
| B. | 0.107 |
| C. | 0.017 |
| D. | 0.215 |
| Answer» E. | |
| 1666. |
The solvent used in liquid extraction should not have high latent heat of vaporisation, because |
| A. | the pressure drop and hence the pumping cost will be very high. |
| B. | it cannot be recovered by distillation. |
| C. | its recovery cost by distillation may be prohibitatively high. |
| D. | it will decompose while recovering by distillation. |
| Answer» D. it will decompose while recovering by distillation. | |
| 1667. |
At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid __________ that in dry packed tower. |
| A. | is greater than |
| B. | is lower than |
| C. | is same as |
| D. | cannot be predicted as data are insufficient |
| Answer» B. is lower than | |
| 1668. |
With increase in gas rate, the number of transfer units, NtoG, for a fixed degree of absorption by a fixed amount of solvent |
| A. | increases |
| B. | decreases |
| C. | decreases linearly |
| D. | remains unaffected |
| Answer» B. decreases | |
| 1669. |
Schmidt number is given by |
| A. | <img src="/_files/images/chemical-engineering/mass-transfer/280-10-1.png"> |
| B. | Re.Pe |
| C. | Sh x Pe |
| D. | Re/Pe |
| Answer» B. Re.Pe | |
| 1670. |
The caking of crystals can be prevented by |
| A. | maintaining high critical humidity. |
| B. | maintaining low critical humidity. |
| C. | coating the product with inert material. |
| D. | both (a) and (c) |
| Answer» E. | |
| 1671. |
Prandtl number for water at 20 C is about |
| A. | 7 |
| B. | 70 |
| C. | 0.7 |
| D. | 150. |
| Answer» B. 70 | |
| 1672. |
Most of the coking coals are |
| A. | anthracite |
| B. | bituminous |
| C. | lignite |
| D. | none of these |
| Answer» C. lignite | |
| 1673. |
Coke compared to the coal from which it has been made, contains |
| A. | less volatile matter. |
| B. | more carbon. |
| C. | greater percentage of ash. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1674. |
A gaseous fuel in order to develop luminousity on burning, must contain |
| A. | carbon monoxide |
| B. | hydrocarbons |
| C. | hydrogen |
| D. | oxygen |
| Answer» C. hydrogen | |
| 1675. |
Gas yield in the Kopper-Totzek coal gasifier is about __________ Nm3/ton coal (ash = 35%). |
| A. | 150 |
| B. | 1500 |
| C. | 3500 |
| D. | 5000 |
| Answer» C. 3500 | |
| 1676. |
Nitrogen present in the flue gas is determined in the orsat apparatus by absorbing it in |
| A. | KOH |
| B. | ammoniacal cuprous chloride |
| C. | pyrogallol solution |
| D. | none of these |
| Answer» E. | |
| 1677. |
The lowest temperature, at which a solid fuel produces enough vapors to support continuous combustion, is called |
| A. | fire point |
| B. | smoke point |
| C. | burning temperature |
| D. | kindling temperature |
| Answer» D. kindling temperature | |
| 1678. |
A coal having high volatile matter content will |
| A. | give less yield of tar and gas on carbonisation. |
| B. | burn with a small non-smoky flame. |
| C. | have a very high calorific value. |
| D. | none of these. |
| Answer» E. | |
| 1679. |
Which of the following petrological constitutes is responsible for bright and lustrous black band of bituminous coal ? |
| A. | Vitrain |
| B. | Clarain |
| C. | Durain |
| D. | Fussain |
| Answer» B. Clarain | |
| 1680. |
A fuel with high heat release rate will |
| A. | require smaller combustion chamber. |
| B. | have high calorific value. |
| C. | have high adiabatic flame temperature. |
| D. | none of these. |
| Answer» B. have high calorific value. | |
| 1681. |
Which of the following is not a by-product fuel? |
| A. | Sewage gas |
| B. | Refinery gas |
| C. | Producer gas |
| D. | Bagasse |
| Answer» D. Bagasse | |
| 1682. |
White flue gas (resembling steam) coming out of the chimney of a thermal power plant indicates that the fuel used in the boiler furnace is |
| A. | tar |
| B. | coke oven gas |
| C. | pitch |
| D. | pulverised coke |
| Answer» C. pitch | |
| 1683. |
Too much of excess air in combustion results in high |
| A. | fuel consumption for the same heat load. |
| B. | stack gas temperature. |
| C. | percentage of oxygen in flue gases. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1684. |
High ash containing coke |
| A. | produces more slag when used in the blast furnace. |
| B. | has poor strength and abrasion resistance. |
| C. | is desirable in producer gas manufacture. |
| D. | none of these. |
| Answer» B. has poor strength and abrasion resistance. | |
| 1685. |
Stoichiometric combustion of 12 kg of carbon requires __________ of oxygen. |
| A. | 1kg mole |
| B. | 22.4 Nm |
| C. | <sup>3</sup> |
| D. | 32 kg |
| E. | all (a), (b) and (c) |
| Answer» E. all (a), (b) and (c) | |
| 1686. |
Coal is pulverised before burning in large capacity boiler furnaces mainly to |
| A. | ensure its complete combustion. |
| B. | facilitate easy ash removal. |
| C. | enhance its calorific value. |
| D. | provide trouble free operation. |
| Answer» B. facilitate easy ash removal. | |
| 1687. |
Calorific value of of blast furnace gas is around __________ KCal/Nm3. |
| A. | 850 |
| B. | 1800 |
| C. | 4200 |
| D. | 6500 |
| Answer» B. 1800 | |
| 1688. |
In low temperature carbonisation of coal as compared to high temperature carbonisation __________ produced is less. |
| A. | difference in gross & net calorific value of the coke oven gas |
| B. | free carbon content in tar |
| C. | yield percentage of coke |
| D. | yield of ammonia present in coke oven gas |
| Answer» B. free carbon content in tar | |
| 1689. |
Coal tar (produced by high temperature carbonisation) is the main source of |
| A. | aromatic compounds |
| B. | alphatic compounds |
| C. | paraffins |
| D. | olefins |
| Answer» B. alphatic compounds | |
| 1690. |
The calorific value is the highest out of the following for |
| A. | producer gas |
| B. | water gas |
| C. | coke oven gas |
| D. | blast furnace gas |
| Answer» D. blast furnace gas | |
| 1691. |
As the C/H ratio of the fuel increases, the amount of CO2 formed on combustion __________ for the same percentage of excess air. |
| A. | decreases |
| B. | increases |
| C. | remains same |
| D. | may increase or decrease depending on the type of fuel |
| Answer» C. remains same | |
| 1692. |
Which of the following fuel gases has the highest calorific value ? |
| A. | Natural gas. |
| B. | Coal bed methane (CBM). |
| C. | Liquefied petroleum gas (LPG). |
| D. | Sewage gas. |
| Answer» D. Sewage gas. | |
| 1693. |
Calorific value as determined by bomb calorimeter is the |
| A. | higher calorific value at constant volume. |
| B. | gross calorific value at constant pressure. |
| C. | lower calorific value at constant pressure. |
| D. | net calorific value at constant volume. |
| Answer» B. gross calorific value at constant pressure. | |
| 1694. |
Fixed carbon in coal is defined as |
| A. | that present in volatile matters. |
| B. | the total quantity of carbon present in the coal. |
| C. | hundred minus the percentage of volatile matter, ash and moisture. |
| D. | the one which is present in the residue after combustion. |
| Answer» D. the one which is present in the residue after combustion. | |
| 1695. |
With increase in the time of carbonisation at a particular temperature (say 1000 C), the __________ percentage in coke oven gas increases. |
| A. | hydrogen |
| B. | methane |
| C. | unsaturated hydrocarbons |
| D. | all (a), (b) and (c) |
| Answer» B. methane | |
| 1696. |
During its calorific value determination by bomb calorimeter, coal is combusted by |
| A. | air |
| B. | oxygen |
| C. | oxygen enriched air |
| D. | none of these |
| Answer» C. oxygen enriched air | |
| 1697. |
Abel apparatus is used for those oils, whose flash points are___ F. |
| A. | <120 |
| B. | >120 |
| C. | >280 |
| D. | 300-600 |
| Answer» B. >120 | |
| 1698. |
Which of the following fuels has the highest calorific value per unit mass (kcal/kg) ? |
| A. | Coal |
| B. | Kerosene |
| C. | Natural gas |
| D. | Furnace oil |
| Answer» E. | |
| 1699. |
What is the value of Joule-Thomson co-efficient for an ideal gas ? |
| A. | +ve |
| B. | -ve |
| C. | 0 |
| D. | |
| Answer» D. | |
| 1700. |
A two stage compressor is used to compress an ideal gas. The gas is cooled to the initial temperature after each stage. The intermediate pressure for the minimum total work requirement should be equal to the __________ mean of P1 and P2.(where, P1 and P2 are initial and final pressures respectively) |
| A. | logarithmic |
| B. | arithmetic |
| C. | geometric |
| D. | harmonic |
| Answer» D. harmonic | |