MCQOPTIONS
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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.
| 1451. |
Blowdown in a cooling tower |
| A. | means discarding a small fraction of circulating water to prevent and limit the concentration of salt and impurities. |
| B. | increases the scale forming tendencies of water. |
| C. | is undesirable. |
| D. | all (a), (b) & (c). |
| Answer» B. increases the scale forming tendencies of water. | |
| 1452. |
During constant rate period, the rate of drying decreases with the |
| A. | decrease in air temperature |
| B. | increase in air humidity |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1453. |
Antibiotics are best handled in a |
| A. | Podbielniak extractor. |
| B. | sieve tray contractor. |
| C. | rotating disc contactor. |
| D. | pulsed column extractor. |
| Answer» B. sieve tray contractor. | |
| 1454. |
The fixed cost of a distillation column at minimum reflux ratio is |
| A. | minimum |
| B. | infinite |
| C. | optimum |
| D. | none of these |
| Answer» C. optimum | |
| 1455. |
In case of constant underflow extraction operation, the __________ at all solute concentration. |
| A. | solids are drained to the same extent |
| B. | ratio of the insoluble to solution is constant |
| C. | both(a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1456. |
In an absorption coloumn, the flooding velocity for random packing is __________ that for stacked/regular packing. |
| A. | greater than |
| B. | smaller than |
| C. | equal to |
| D. | either (a), or (b) ; depends on the type of packing |
| Answer» C. equal to | |
| 1457. |
With increase in temperature, the leaching rate increases because of the |
| A. | increased diffusivity. |
| B. | decreased viscosity of liquid. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1458. |
Which of the following is an undesirable property in a tower packing ? |
| A. | Large surface per unit volume. |
| B. | Large free cross-section. |
| C. | Low weight per unit volume. |
| D. | Large weight of liquid retained. |
| Answer» E. | |
| 1459. |
A 25 cm x 25 cm x 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m x 1m x 1cm flat sheet of the same material is to be dried from one side only.Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is |
| A. | 1000 |
| B. | 1500 |
| C. | 2000 |
| D. | 2500 |
| Answer» B. 1500 | |
| 1460. |
With increase in temperature, the rate of leaching increases, because the |
| A. | diffusivity of solute increases. |
| B. | viscosity of solvent decreases. |
| C. | thermal conductivity of solute increases. |
| D. | none of these. |
| Answer» B. viscosity of solvent decreases. | |
| 1461. |
Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of __________ humidity. |
| A. | molal |
| B. | relative |
| C. | percentage |
| D. | none of these |
| Answer» B. relative | |
| 1462. |
Water entrained by circulating air in cooling towers is termed as |
| A. | drift |
| B. | blow down |
| C. | vapor load |
| D. | none of these. |
| Answer» B. blow down | |
| 1463. |
Pressure drop through plate tower as compared to that through packed tower, for the same duty will be |
| A. | less |
| B. | more |
| C. | equal |
| D. | either (a) or (b); depends on the packing height |
| Answer» C. equal | |
| 1464. |
Large scale drying of wheat is done in a __________ dryer. |
| A. | fluidised bed |
| B. | spouted bed |
| C. | tray |
| D. | vacuum rotary |
| Answer» C. tray | |
| 1465. |
Azeotropic distillation is employed to separate |
| A. | constant boiling mixture. |
| B. | high boiling mixture. |
| C. | mixture with very high relative volatility. |
| D. | heat sensitive materials. |
| Answer» B. high boiling mixture. | |
| 1466. |
With increase in C/H ratio of a fuel, the dew point of flue gases |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | may increase or decrease ; depends on the type of fuel |
| Answer» C. remains same | |
| 1467. |
A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that |
| A. | 21% excess air has been used for combustion. |
| B. | 21% excess oxygen has been used for combustion. |
| C. | complete combustion of fuel has taken place. |
| D. | no excess air has been used for combustion. |
| Answer» D. no excess air has been used for combustion. | |
| 1468. |
Fusion point of coal ash generally varies from 1000 to 1700 C. Ash having fusion point less than __________ C is liable to form clinker. |
| A. | 1100 |
| B. | 1250 |
| C. | 1350 |
| D. | 1400 |
| Answer» B. 1250 | |
| 1469. |
Light oil whose major component is benzol, is obtained by the distillation of crude tar in the temperature range of __________ C. |
| A. | 80-170 |
| B. | 200-300 |
| C. | 250-270 |
| D. | 280-300 |
| Answer» B. 200-300 | |
| 1470. |
Power alcohol as compared to straight run gasoline has lower |
| A. | calorific value |
| B. | octane number |
| C. | specific gravity |
| D. | viscosity |
| Answer» B. octane number | |
| 1471. |
When the coal is heated in absence of air, it is called its |
| A. | deoxidation |
| B. | gasification |
| C. | coalification |
| D. | carbonisation |
| Answer» E. | |
| 1472. |
Bunsen burner is an example of a/an __________ burner. |
| A. | inside mixing/premix type |
| B. | outside mixing/diffusion flame/nozzle mix type. |
| C. | rotary cup. |
| D. | submerged combustion. |
| Answer» B. outside mixing/diffusion flame/nozzle mix type. | |
| 1473. |
With increase in C/H ratio of a fuel, the amount of CO2 formed on its complete combustion |
| A. | increases |
| B. | decreases |
| C. | remains same |
| D. | either (a) or (b), depends on other factors |
| Answer» B. decreases | |
| 1474. |
Which of the following is the maximum coal producing state in India ? |
| A. | Orissa |
| B. | West Bengal |
| C. | Jharkhand |
| D. | Assam |
| Answer» D. Assam | |
| 1475. |
Height of coke oven is limited (say maximum upto 7 metres) mainly by the |
| A. | problem of uniform heating along its height. |
| B. | structural strength of silica bricks. |
| C. | problem in door cleaning. |
| D. | buckling of ram of pusher car at the time of coke pushing. |
| Answer» B. structural strength of silica bricks. | |
| 1476. |
Out of the following fuels, the difference between the net and gross calorific value is maximum in case of |
| A. | pitch |
| B. | fuel oil |
| C. | blast furnace gas |
| D. | bituminous coal |
| Answer» C. blast furnace gas | |
| 1477. |
The hottest part of the flame lies in its____zone. |
| A. | non-luminous |
| B. | luminous |
| C. | yellow |
| D. | unburnt gases |
| Answer» B. luminous | |
| 1478. |
Which of the following has the highest calorific value ? |
| A. | Lignite |
| B. | Sub-bituminous coal |
| C. | Anthracite |
| D. | Peat |
| Answer» D. Peat | |
| 1479. |
Cannel coal and boghead coal are the examples of |
| A. | humic coals |
| B. | liptobiolites |
| C. | sapropelic coals |
| D. | none of these |
| Answer» D. none of these | |
| 1480. |
The calorific value of producer gas is around __________ kcal/Nm3 |
| A. | 1300 |
| B. | 500 |
| C. | 4500 |
| D. | 9000 |
| Answer» B. 500 | |
| 1481. |
About __________ Nm3 of air will be required for the complete combustion of 2Nm3 of CO. |
| A. | 2 |
| B. | 3 |
| C. | 5 |
| D. | 1 |
| Answer» D. 1 | |
| 1482. |
Coking time in beehive coke oven is about |
| A. | 12 hours |
| B. | 2-3 days |
| C. | one week |
| D. | two weeks |
| Answer» C. one week | |
| 1483. |
Presence of free moisture in coal is most disadvantageous during |
| A. | its pulverisation (as it requires more power). |
| B. | combustion of fire slacks on the grates. |
| C. | handling (e.g. when emptying wagons). |
| D. | none of these. |
| Answer» B. combustion of fire slacks on the grates. | |
| 1484. |
The heat of combustion of a fuel |
| A. | is equal to the heat of formation. |
| B. | is always negative. |
| C. | can't be known without calculating it. |
| D. | is always positive. |
| Answer» C. can't be known without calculating it. | |
| 1485. |
High excess air in combustion of fuels results in |
| A. | increased fuel consumption |
| B. | incomplete combustion |
| C. | smoky flame |
| D. | none of these |
| Answer» B. incomplete combustion | |
| 1486. |
Abrasion index of blast furnace coke should be around __________ percent. |
| A. | 20 |
| B. | 35 |
| C. | 55 |
| D. | 80 |
| Answer» E. | |
| 1487. |
Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent. |
| A. | 3 & 10 |
| B. | 10 & 3 |
| C. | 10 & 20 |
| D. | 15 & 8 |
| Answer» C. 10 & 20 | |
| 1488. |
Caking index of the coal blend used for the manufacture of metallurgical coke should be around |
| A. | 5 |
| B. | 21 |
| C. | 40 |
| D. | 48 |
| Answer» C. 40 | |
| 1489. |
With increase in moisture content of coal, its |
| A. | calorific value increases sometimes. |
| B. | bulk density always decreases. |
| C. | clinkering tendency during combustion increases. |
| D. | none of these. |
| Answer» E. | |
| 1490. |
In flue gas analysis by Orsat's apparatus, carbon dioxide is absorbed by |
| A. | potassium hydroxide. |
| B. | dilute potassium carbonate. |
| C. | cuporus chloride. |
| D. | alkaline pyragllol solution. |
| Answer» B. dilute potassium carbonate. | |
| 1491. |
The calorific value of 'LPG' (50% propane + 50% butane) is about __________ kcal/Nm3. |
| A. | 5000 |
| B. | 25, 000 |
| C. | 10, 000 |
| D. | 15, 000 |
| Answer» C. 10, 000 | |
| 1492. |
Which of the following petrographic constituents of coal is non-coking ? |
| A. | Vitrain |
| B. | Clarain |
| C. | Durain |
| D. | Fussain |
| Answer» E. | |
| 1493. |
__________ has the widest inflammability limit (explosion limit) of all the gases. |
| A. | Hydrogen |
| B. | Carbon monoxide |
| C. | Acetylene |
| D. | Methane |
| Answer» D. Methane | |
| 1494. |
Percentage of methane in coke oven gas may be around |
| A. | 5 |
| B. | 15 |
| C. | 25 |
| D. | 50 |
| Answer» D. 50 | |
| 1495. |
Higher fuel combustion efficiency can not be achieved by |
| A. | preheating of fuel gases & combustion air. |
| B. | reducing sulphur content in the fuel. |
| C. | adopting proper fuel firing technique & fuel preparation. |
| D. | supplying correct amount of combustion air. |
| Answer» C. adopting proper fuel firing technique & fuel preparation. | |
| 1496. |
__________ present in coal is not determined in its ultimate analysis. |
| A. | Fixed carbon |
| B. | Total carbon |
| C. | Hydrogen |
| D. | Nitrogen. |
| Answer» B. Total carbon | |
| 1497. |
The calorific value of L.D. converter gas is about __________ Kcal/Nm3 . |
| A. | 1800 |
| B. | 800 |
| C. | 4500 |
| D. | 10000 |
| Answer» B. 800 | |
| 1498. |
__________ prohibits the use of alcohols directly in petrol engines. |
| A. | Low octane number |
| B. | High cost & availability |
| C. | Low flash point |
| D. | Low calorific value |
| Answer» C. Low flash point | |
| 1499. |
C.V. (kcal/Nm3) of gaseous fuels __________ with increase in molecular weight. |
| A. | decreases |
| B. | increases |
| C. | remains constant |
| D. | may increase or decrease, depends on combustibles. |
| Answer» E. | |
| 1500. |
Shatter index of the coke is a measure of its |
| A. | strength |
| B. | bulk density |
| C. | reactivity |
| D. | none of these |
| Answer» B. bulk density | |