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.
| 1351. |
Oxygen percentage (by weight) in atmospheric air is |
| A. | 19 |
| B. | 21 |
| C. | 23 |
| D. | 29 |
| Answer» D. 29 | |
| 1352. |
__________ of the coal is the basis for Seylor's coal classification. |
| A. | Proximate analysis |
| B. | Ultimate analysis |
| C. | Caking index |
| D. | Calorific value |
| Answer» C. Caking index | |
| 1353. |
'Fat' coal means a coal having |
| A. | low calorific value. |
| B. | high volatile matter, |
| C. | low ash content. |
| D. | non smoking tendency. |
| Answer» C. low ash content. | |
| 1354. |
Main constituents of benzol are |
| A. | benzene, toluene & xylene. |
| B. | tar & creosote. |
| C. | ammonia & phenol. |
| D. | anthracene & phenol. |
| Answer» B. tar & creosote. | |
| 1355. |
Softening temperature of coal ash is a measure of the __________ of coal. |
| A. | caking tendency |
| B. | coking tendency |
| C. | clinkering tendency |
| D. | size stability |
| Answer» D. size stability | |
| 1356. |
A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be |
| A. | more |
| B. | less |
| C. | same |
| D. | data insufficient; can't be predicted. |
| Answer» D. data insufficient; can't be predicted. | |
| 1357. |
Initial pressure of oxygen introduced into the 'bomb' of the bomb calorimeter for determination of calorific value of coal/fuel oil may be around __________ atm. |
| A. | 3-5 |
| B. | 25-30 |
| C. | 60-65 |
| D. | 95-100 |
| Answer» C. 60-65 | |
| 1358. |
Presence of phosphorous in metallurgical coal |
| A. | is not undersirable. |
| B. | reduces its calorific value. |
| C. | badly affects the quality of steel. |
| D. | increases its caking power. |
| Answer» D. increases its caking power. | |
| 1359. |
"Overfire burning" in a furnace is a phenomenon characterised by the |
| A. | supply of excess fuel. |
| B. | supply of excess air. |
| C. | burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air. |
| D. | none of these. |
| Answer» D. none of these. | |
| 1360. |
Which of the following fertilisers is produced in the by-products recovery (from coke oven gas) plant attached to an integrated steel plant ? |
| A. | Ammonium sulphate |
| B. | Ammonium nitrate |
| C. | Ammonium phosphate |
| D. | None of these |
| Answer» B. Ammonium nitrate | |
| 1361. |
High ash coals |
| A. | are soft & friable (poor strength and size stability). |
| B. | require longer time of carbonisation as ash offers resistance to heat transfer. |
| C. | produce larger quantity of coke oven gas. |
| D. | none of these. |
| Answer» C. produce larger quantity of coke oven gas. | |
| 1362. |
Which of the following is not a by-product fuel ? |
| A. | Pitch |
| B. | Blast furnace gas |
| C. | Petrol |
| D. | Refinery gas |
| Answer» D. Refinery gas | |
| 1363. |
Preheating of combustion air is done to |
| A. | increase the adiabatic flame temperature. |
| B. | increase the calorific value of the fuel. |
| C. | complete the combustion of fuel. |
| D. | reduce its requirement for effecting the complete combustion. |
| Answer» B. increase the calorific value of the fuel. | |
| 1364. |
Anthracite can be used for |
| A. | recarbonising steel. |
| B. | making carbon electrodes; |
| C. | blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1365. |
Which of the following is not a 'manufactured' fuel ? |
| A. | LPG |
| B. | Coal briquettes |
| C. | Tar |
| D. | Colloidal fuels |
| Answer» D. Colloidal fuels | |
| 1366. |
Use of excess of combustion air in the combustion of fuels results in |
| A. | heat losses. |
| B. | long flame. |
| C. | condensation of water vapour from the fuel gas. |
| D. | none of these. |
| Answer» B. long flame. | |
| 1367. |
Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing ? |
| A. | Ash disposal problem. |
| B. | Excessive fly-ash discharge from the stack. |
| C. | High power consumption in its transportation. |
| D. | Erosion of induced draft fan blades. |
| Answer» B. Excessive fly-ash discharge from the stack. | |
| 1368. |
Calorific value of both the solid & liquid fuels can be determined by using __________ calorimeter. |
| A. | Junker's |
| B. | Bomb |
| C. | Boy's |
| D. | none of these |
| Answer» C. Boy's | |
| 1369. |
Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has |
| A. | higher calorific value. |
| B. | lower hydrogen content. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» E. | |
| 1370. |
Use of pulverised coal in boiler furnace provides |
| A. | high calorific value. |
| B. | better combustion. |
| C. | smokeless burning. |
| D. | less erosion on furnace walls. |
| Answer» C. smokeless burning. | |
| 1371. |
Deficiency of combustion air during combustion of a gaseous fuel |
| A. | lengthens the flame. |
| B. | causes heat loss of fuel by its partial combustion. |
| C. | both (a) & (b). |
| D. | shortens the flame. |
| Answer» D. shortens the flame. | |
| 1372. |
Froth floatation is used for |
| A. | washing fine coal dust (< 0.5 mm size). |
| B. | washing lump coal (> 80 mm size). |
| C. | removing ash from the coal based on difference in specific gravity of coal and ash. |
| D. | all (a), (b)and(c). |
| Answer» B. washing lump coal (> 80 mm size). | |
| 1373. |
Quantity of coke oven gas produced by high temperature carbonisation of one ton of dry coal may be around __________ Nm3 . |
| A. | 30 |
| B. | 300 |
| C. | 3000 |
| D. | 30, 000 |
| Answer» C. 3000 | |
| 1374. |
Coking coals are invariably |
| A. | lignites |
| B. | bituminous coals |
| C. | semi-anthracites |
| D. | anthracites |
| Answer» C. semi-anthracites | |
| 1375. |
'Fuel' can be defined as a substance which produces heat by |
| A. | combustion. |
| B. | nuclear fission. |
| C. | nuclear fusion. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 1376. |
Which of the following accounts for maximum energy loss in a boiler ? |
| A. | Flue gases. |
| B. | Ash content in the fuel. |
| C. | Incomplete combustion. |
| D. | Unburnt carbon in flue gases. |
| Answer» B. Ash content in the fuel. | |
| 1377. |
Fuel consumption in coke making can be reduced by |
| A. | preheating, blending and de-ashing the coal. |
| B. | stamped charging of coal. |
| C. | dry quenching of coke. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1378. |
When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2, it is called the __________ of coal. |
| A. | carbonisation |
| B. | oxidation |
| C. | coalification |
| D. | gasification |
| Answer» E. | |
| 1379. |
A travelling grate stoker is meant for the efficient burning of __________ coal. |
| A. | caking |
| B. | pulverised |
| C. | non-caking |
| D. | high ash |
| Answer» D. high ash | |
| 1380. |
Traces of tar fog present in the coke oven gas is removed by |
| A. | cyclone separator. |
| B. | wet packed scrubber. |
| C. | electrostatic precipitator. |
| D. | washing with monoethanolamine. |
| Answer» D. washing with monoethanolamine. | |
| 1381. |
Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its |
| A. | emissivity factor is higher. |
| B. | sulphur content is lower. |
| C. | flue gas has lower dew point thereby facilitating more waste heat recovery. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1382. |
Ionisation potential applied across the electrodes of electrostatic tar precipitator is around |
| A. | 230 V AC |
| B. | 60 KV AC |
| C. | 230 V DC |
| D. | 60 KV DC |
| Answer» E. | |
| 1383. |
Optimum preheating temperature for pitch creosote mixture (PCM) which is also termed as C.T.F-200, before atomisation through burners is |
| A. | 200 F |
| B. | 200 C |
| C. | 200 K |
| D. | 200 R |
| Answer» B. 200 C | |
| 1384. |
Benzol is used |
| A. | as a motor fuel blend. |
| B. | for producing benzene, tolune & xylene by its distillation. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1385. |
Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent. |
| A. | 6 |
| B. | 12 |
| C. | 18 |
| D. | 24 |
| Answer» E. | |
| 1386. |
Which of the following is not endothermic? |
| A. | Cracking |
| B. | Reforming |
| C. | Gasification |
| D. | Partial oxidation |
| Answer» E. | |
| 1387. |
High sulphur content in a fuel __________ of the flue gases. |
| A. | decreases the dew point |
| B. | increases the dew point |
| C. | reduces the combustion efficiency by limiting the permissible temperature reduction |
| D. | , both (b) and (c) |
| Answer» E. | |
| 1388. |
Ash content in the middling coal (a byproduct of coal washeries) in India ranges between __________ percent. |
| A. | 15 to 25 |
| B. | 35 to 45 |
| C. | 55 to 75 |
| D. | 75 |
| Answer» C. 55 to 75 | |
| 1389. |
Fuel combustion is never cent per cent efficient due to |
| A. | incomplete combustion |
| B. | dry gas/stack gas loss |
| C. | moisture loss |
| D. | all (a), (b) and (c) |
| Answer» E. | |
| 1390. |
Percentage of nitrogen in blast furnace gas may be around |
| A. | 5 |
| B. | 25 |
| C. | 55 |
| D. | 80 |
| Answer» D. 80 | |
| 1391. |
Very __________ coals are completely devoid of cokability i.e, it is non coking. |
| A. | young |
| B. | mature |
| C. | both 'a' & 'b' |
| D. | neither 'a' nor 'b' |
| Answer» D. neither 'a' nor 'b' | |
| 1392. |
Nitrogen in coal |
| A. | is present upto 1-2%. |
| B. | comes from protein in parent vegetable matter. |
| C. | is recovered as ammonia during its carbonisation. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1393. |
The fuel ratio of a coal is |
| A. | the ratio of its percentage of fixed carbon to that of volatile matter. |
| B. | helpful in estimation of its rank. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1394. |
Which of the following fuel gases will require maximum amount of air for combustion of 1 Nm3 gas ? |
| A. | Blast furnace gas |
| B. | Natural gas |
| C. | Producer gas |
| D. | Water gas |
| Answer» C. Producer gas | |
| 1395. |
High rate of heating of coke ovens |
| A. | may damage its walls due to abrupt excessive swelling of coal. |
| B. | produces larger size coke. |
| C. | increases the time of carbonisation. |
| D. | none of these. |
| Answer» B. produces larger size coke. | |
| 1396. |
A certain thickness of the coal, if stored unscientifically on soft (katcha) ground having no metallic/concrete flooring gets sunked into the ground, which is termed as the 'carpet loss'. The carpet loss may be of the order of __________ cms. |
| A. | 1 to 2 |
| B. | 3 to 4 |
| C. | 5 to 15 |
| D. | 20 to 40 |
| Answer» D. 20 to 40 | |
| 1397. |
Gray-King Assay and Roga Index of coal is a measure of its |
| A. | abradability. |
| B. | grindability. |
| C. | weathering properties. |
| D. | caking and swelling properties. |
| Answer» E. | |
| 1398. |
While the first commercial low temperature coal carbonisation plant is located at Neyveli (in Chennai), the second such plant has been built at |
| A. | Dankuni (West Bengal) |
| B. | Dhanbad |
| C. | Singreni (AP.) |
| D. | Raniganj |
| Answer» B. Dhanbad | |
| 1399. |
Coal tar fuels (CTF) as compared to petroleum based fuel oils have higher |
| A. | calorific value |
| B. | higher C/H ratio |
| C. | sulphur content |
| D. | difference in gross & net calorific value |
| Answer» C. sulphur content | |
| 1400. |
Main use of soft coke is as __________ fuel. |
| A. | domestic |
| B. | blastfurnace |
| C. | foundary |
| D. | none of these |
| Answer» B. blastfurnace | |