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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.
| 1301. |
The main advantage of forced draft over natural draft is that |
| A. | combustion of fuel is complete. |
| B. | smaller height chimney can be used. |
| C. | furnace control is easier. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 1302. |
Benzene is used |
| A. | as a motor fuel. |
| B. | as an explosive. |
| C. | for making insecticides (e.g., DDT, BHC etc.), detergent & rubber (SBR). |
| D. | as a perfume. |
| Answer» D. as a perfume. | |
| 1303. |
Naphthalene is used for making |
| A. | insecticides (e.g. moth balls). |
| B. | unsaturated polyesters. |
| C. | drug intermediates e.g. -naphthol. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1304. |
The advantage of firing pulverised coal in the furnace lies in the fact, that it |
| A. | permits the use of high ash content coal. |
| B. | permits the use of low fusion point ash coal. |
| C. | accelerates the burning rate and economises on fuel combustion. |
| D. | all (a), (b) and (c). |
| Answer» D. all (a), (b) and (c). | |
| 1305. |
A coal having higher volatile matter content, has lower |
| A. | smoking tendency on burning. |
| B. | coke oven gas yield on carbonisation. |
| C. | chance of catching fire during storage in open space. |
| D. | ignition temperature. |
| Answer» E. | |
| 1306. |
Weathering of coal during storage causes |
| A. | reduction in coal size. |
| B. | increase in its friability. |
| C. | decrease in its caking capacity. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1307. |
Which of the following has the highest gross calorific value ? |
| A. | Blast furnace gas |
| B. | Coke oven gas |
| C. | Carburetted water gas |
| D. | Oil refinery gas |
| Answer» E. | |
| 1308. |
A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the |
| A. | presence of large quantity of hydrogen in the fuel. |
| B. | low calorific value of the fuel. |
| C. | high sulphur content in the fuel. |
| D. | lack of thorough mixing of fuel with air. |
| Answer» E. | |
| 1309. |
Efficient burning of anthracite coal requires |
| A. | low preheat of air. |
| B. | fine grinding. |
| C. | high excess air. |
| D. | all (a), (b) and (c). |
| Answer» C. high excess air. | |
| 1310. |
C/H ratio is the minimum in case of |
| A. | furnace oil |
| B. | natural gas |
| C. | coal |
| D. | naphtha |
| Answer» C. coal | |
| 1311. |
In flue gas analysis by Orsat's apparatus, oxygen is absorbed by |
| A. | potassium hydroxide. |
| B. | cuprous chloride. |
| C. | alkaline pyragllol solution. |
| D. | none of these. |
| Answer» D. none of these. | |
| 1312. |
Natural draft created by the chimney depends upon |
| A. | temperature of the flue gas. |
| B. | its height. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1313. |
Which of the following fuel gases is heavier than air ? |
| A. | Blast furnace gas |
| B. | Coke oven gas |
| C. | Natural gas |
| D. | Water gas |
| Answer» B. Coke oven gas | |
| 1314. |
Theoretical flame temperature of a fuel is that temperature which is attained, when the fuel is completely burnt 'using theoretical amount of air in |
| A. | air |
| B. | oxygen |
| C. | either (a) or (b) |
| D. | either (a) or (b) without gain or loss of heat |
| Answer» E. | |
| 1315. |
Use of preheated air for combustion of fuel in the furnace, increases the |
| A. | scale losses of the furnace stock. |
| B. | calorific value of the fuel. |
| C. | flame temperature. |
| D. | none of these. |
| Answer» D. none of these. | |
| 1316. |
Calorific value of a typical dry anthracite coal may be around __________ Kcal/kg. |
| A. | 1000 |
| B. | 4000 |
| C. | 8000 |
| D. | 15000 |
| Answer» D. 15000 | |
| 1317. |
The most matured coal out of the following is |
| A. | lignite |
| B. | semi-anthracite |
| C. | sub-bituminous |
| D. | bituminous |
| Answer» C. sub-bituminous | |
| 1318. |
Lurgi gasifier (high pressure gasifier) as compared to Kopper Totzek gasifier (atmospheric pressure gasifier) produces |
| A. | higher amount of methane. |
| B. | lower amount of hydrogen. |
| C. | both (a) and (b). |
| D. | higher amount of both methane and hydrogen. |
| Answer» D. higher amount of both methane and hydrogen. | |
| 1319. |
For long flame and easy ignition, the coal used should have |
| A. | high volatile matter |
| B. | low ash |
| C. | high calorific value |
| D. | high ash |
| Answer» B. low ash | |
| 1320. |
Coke oven gas after passing through return electrostatic tar precipitator (RETP) is used for the |
| A. | hot scarfing of steel slabs. |
| B. | mixing with blast furnace gas. |
| C. | coke oven battery heating. |
| D. | steel ladle drying. |
| Answer» D. steel ladle drying. | |
| 1321. |
Which of the following has the highest calorific value (kcal/Nm3) ? |
| A. | Carburetted water gas |
| B. | Gobar gas |
| C. | Natural gas |
| D. | LPG |
| Answer» E. | |
| 1322. |
A coal gasifier opearating at 20 atm. (e.g. Lugri gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having |
| A. | higher methane content and thus higher calorific value. |
| B. | higher carbon monoxide content. |
| C. | lower carbon dioxide content. |
| D. | none of these. |
| Answer» B. higher carbon monoxide content. | |
| 1323. |
In low temperature carbonisation (as compared to high temperature carbonisation) of coal |
| A. | ammonia yield is more. |
| B. | aliphatic tar is produced. |
| C. | free carbon in tar is more. |
| D. | all (a), (b) and (c). |
| Answer» C. free carbon in tar is more. | |
| 1324. |
Combustion of pulverised fuel |
| A. | requires larger combustion chamber than rich gaseous fuel. |
| B. | in a metallurgical furnace does not contaminate the product in the furnace by ash from fuel. |
| C. | suppresses the discharge of fine dust and grit into atmosphere |
| D. | all (a), (b) and (c) |
| Answer» B. in a metallurgical furnace does not contaminate the product in the furnace by ash from fuel. | |
| 1325. |
Low temperature oxidation of coal during storage does not decrease its |
| A. | oxygen content |
| B. | caking power |
| C. | calorific value |
| D. | none of these |
| Answer» E. | |
| 1326. |
With increase in the oxygen content of the coal, its __________ decreases. |
| A. | calorific value |
| B. | caking power |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1327. |
Bomb calorimeter can be used to determine the __________ of the coal. |
| A. | sulphur content |
| B. | calorific value |
| C. | both(a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1328. |
Which of the following is a poisonous fuel gas? |
| A. | Coke oven gas |
| B. | Blast furnace gas |
| C. | Natural gas |
| D. | None of these |
| Answer» C. Natural gas | |
| 1329. |
Washing of coal does not reduce its |
| A. | S & P content. |
| B. | heating value. |
| C. | fusion point of ash. |
| D. | none of these. |
| Answer» E. | |
| 1330. |
A coal that softens and fuses on heating is |
| A. | classified |
| B. | carbonised |
| C. | caking |
| D. | non-caking |
| Answer» D. non-caking | |
| 1331. |
'Mixed gas' used in steel plants is a mixture of |
| A. | B.F. gas and coke oven gas. |
| B. | coke oven gas and converter gas. |
| C. | coke oven gas and L.P.G. |
| D. | blast furnace gas and naphtha vapor. |
| Answer» B. coke oven gas and converter gas. | |
| 1332. |
Calorific value of |
| A. | light paraffinic fuel oils is equal to that of equivalent olefins. |
| B. | n-paraffin is lower than that of iso-paraffins of the same compounds. |
| C. | light paraffinic fuel oils is higher than that of equivalent olefins. |
| D. | light paraffinic fuel oils is lower than that of equivalent olefins. |
| Answer» D. light paraffinic fuel oils is lower than that of equivalent olefins. | |
| 1333. |
Which of the following would require least amount of secondary air for combustion ? |
| A. | Coke breeze containing 25% ash and 2% volatile matter. |
| B. | Anthracite containing 10% volatile matter and 8% ash. |
| C. | Bituminous coal containing 20% ash and 25% volatile matter. |
| D. | Semi-bituminous coal containing 25% ash and 20% volatile matter. |
| Answer» B. Anthracite containing 10% volatile matter and 8% ash. | |
| 1334. |
'Fat coals' are those coals which have very high |
| A. | caking capacity. |
| B. | volatile matter content. |
| C. | fusion point of its ash. |
| D. | inherent moisture content. |
| Answer» B. volatile matter content. | |
| 1335. |
A coal with high ash content |
| A. | has higher calorific value. |
| B. | is harder and stronger. |
| C. | is not subjected to washing. |
| D. | has low quantity of mineral matter. |
| Answer» C. is not subjected to washing. | |
| 1336. |
Preheating of coal charge for the coke ovens reduces the |
| A. | time of carbonisation. |
| B. | yield of gas and tar. |
| C. | fuel consumption in coking. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1337. |
Which of the following is the most poisonous gas ? |
| A. | Coke oven gas |
| B. | Producer gas |
| C. | Blast furnace gas |
| D. | L.D. converter gas |
| Answer» E. | |
| 1338. |
Preheating of a gaseous fuel results in increased |
| A. | flame length |
| B. | flame temperature |
| C. | quantity of flue gas |
| D. | ignition temperature |
| Answer» C. quantity of flue gas | |
| 1339. |
Fossil fuels mean |
| A. | solid fuels |
| B. | liquid fuels |
| C. | those fuels which are found in the crust of earth. |
| D. | premature fuels with low calorific value. |
| Answer» D. premature fuels with low calorific value. | |
| 1340. |
Highly caking coals |
| A. | produce weak coke. |
| B. | produce strong coke. |
| C. | may damage the coke oven walls during carbonisation. |
| D. | both (b) and (c). |
| Answer» E. | |
| 1341. |
Calorific value of coke oven gas is around __________ Kcal/Nm3. |
| A. | 900 |
| B. | 4200 |
| C. | 7500 |
| D. | 2000 |
| Answer» C. 7500 | |
| 1342. |
Main use of hard coke produced by high temperature carbonisation is in the |
| A. | iron blast furnace |
| B. | cupola in foundaries |
| C. | sinter making |
| D. | domestic ovens |
| Answer» B. cupola in foundaries | |
| 1343. |
Hard pitch is used for making |
| A. | pulverised fuel |
| B. | perfumes |
| C. | insecticides |
| D. | plastics |
| Answer» B. perfumes | |
| 1344. |
__________ process is meant for direct hydrogenation of coal to produce liquid fuel. |
| A. | Fischer-Tropsch |
| B. | Bergius |
| C. | Lurgi |
| D. | None of these |
| Answer» C. Lurgi | |
| 1345. |
Producer gas containing least amount of tar is produced by the |
| A. | partial combustion of coal. |
| B. | partial combustion of large size (< 50 mm) coke. |
| C. | high pressure gasification of coal (e.g. in Lurgi gasifier). |
| D. | atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier). |
| Answer» C. high pressure gasification of coal (e.g. in Lurgi gasifier). | |
| 1346. |
Air/gas ratio for complete combustion will be the highest for |
| A. | LPG |
| B. | gobar gas |
| C. | coke oven gas |
| D. | carburetted water gas |
| Answer» B. gobar gas | |
| 1347. |
Beehive coke oven |
| A. | facilitates by-products recovery. |
| B. | takes 2-3 days for coking of coal but requires no external fuel for heating. |
| C. | gives larger yield of coke (around 85%) as compared to by-product ovens. |
| D. | produces coke with very poor strength. |
| Answer» C. gives larger yield of coke (around 85%) as compared to by-product ovens. | |
| 1348. |
Turndown ratio of a gas burner is equal to the |
| A. | maximum to minimum heat input ratio. |
| B. | maximum to minimum permissible gas flow rate. |
| C. | both (a) & (b). |
| D. | minimum to maximum heat input ratio. |
| Answer» D. minimum to maximum heat input ratio. | |
| 1349. |
Atomising steam to fuel oil ratio in a burner should be around |
| A. | 0.5 |
| B. | 1.5 |
| C. | 2.5 |
| D. | 3.5 |
| Answer» B. 1.5 | |
| 1350. |
Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is |
| A. | 20 |
| B. | 12.5 |
| C. | 0 |
| D. | 10 |
| Answer» D. 10 | |