

MCQOPTIONS
Saved Bookmarks
This section includes 408 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
201. |
In low temperature carbonisation of coal, the________________? |
A. | Yield of coke oven gas is 290 Nm3 /ton dry coal |
B. | Volatile matter in coke is zero |
C. | Temperature maintained is 700°C |
D. | Yield of tar is about 3% of dry coal |
Answer» D. Yield of tar is about 3% of dry coal | |
202. |
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 | |
203. |
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 | |
204. |
In high temperature carbonisation of coal compared to low temperature carbonisation ? |
A. | Yield of ammonia is less |
B. | Aromatic content of tar is low |
C. | H2 content in the coke oven gas is more |
D. | Calorific value of the coke oven gas is lower |
Answer» D. Calorific value of the coke oven gas is lower | |
205. |
In high temperature carbonisation (as compared to low temperature carbonisation) of coal___________________? |
A. | Coke oven gas yield is more |
B. | Tar yield is less but free carbon in tar is more |
C. | Calorific value of coke oven gas is less |
D. | All A., B. and C. |
Answer» E. | |
206. |
In high temperature carbonisation (as compared to low temperature carbonisation) of coal, the______________? |
A. | Gas yield is less |
B. | Tar yield is more |
C. | Ignition temperature of coke produced is less |
D. | Aromatic content of tar produced is more |
Answer» E. | |
207. |
In general, the limit of inflammability/explosion limit of fuel gases is widened by the__________________? |
A. | Increase in gas pressure |
B. | Increase in temperature (i.e. preheating) |
C. | Use of pure oxygen for combustion instead of air |
D. | All A., B. & C. |
Answer» E. | |
208. |
In flue gas analysis by Orsat’s apparatus, oxygen is absorbed by____________________? |
A. | Potassium hydroxide |
B. | Cuprous chloride |
C. | Alkaline pyrogallol solution |
D. | None of these |
Answer» D. None of these | |
209. |
In flue gas analysis by Orsat’s apparatus, carbon monoxide is absorbed by__________________? |
A. | Cuprous chloride |
B. | Potassium hydroxide |
C. | Alkaline pyrogallol solution |
D. | None of these |
Answer» B. Potassium hydroxide | |
210. |
In flue gas analysis by Orsat’s apparatus, carbon dioxide is absorbed by______________________? |
A. | Potassium hydroxide |
B. | Dilute potassium carbonate |
C. | Cuprous chloride |
D. | Alkaline pyrogallol solution |
Answer» B. Dilute potassium carbonate | |
211. |
In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of__________________? |
A. | Transportation of coal |
B. | Drying of coal |
C. | Combustion of coal by supplying it around the burner |
D. | Preheating the primary air |
Answer» D. Preheating the primary air | |
212. |
Improper storage condition results in the weathering of coal and spontaneous combustion, which increases its_________________? |
A. | Caking index |
B. | Yield of carbonised products |
C. | Friability & oxygen content |
D. | Calorific value |
Answer» D. Calorific value | |
213. |
Ignition temperature decreases progressively from anthracite to lignite, because___________________? |
A. | Volatile matter content increases |
B. | Carbon content decreases |
C. | Moisture content increases |
D. | Ash content increases |
Answer» B. Carbon content decreases | |
214. |
Ignition temperature of a fuel in air is ______________ that in pure oxygen? |
A. | More than |
B. | Less than |
C. | Equal to |
D. | Either more or less; depends on the type of fuel |
Answer» B. Less than | |
215. |
If the specific heat of gaseous products of combustion of a fuel is high, the abiabatic flame temperature will be_____________? |
A. | Low |
B. | High |
C. | Very high, if the fuel is of low calorific value |
D. | None of these |
Answer» B. High | |
216. |
If oxygen content in the flue gas rises too high, fuel is being wasted by _______________? |
A. | Incomplete combustion |
B. | Dry gas/stack gas loss |
C. | Moisture loss |
D. | None of these |
Answer» C. Moisture loss | |
217. |
If CO2 is not fully absorbed by the KOH solution meant for its absorption in the orsat apparatus, it will appear as___________________? |
A. | O2 |
B. | CO |
C. | N2 |
D. | SO2 |
Answer» E. | |
218. |
Highly reactive coke have lower ___________________? |
A. | Porosity |
B. | Coke reactivity index (CRI) |
C. | Critical air blast (CAB) value |
D. | Both B. and C. |
Answer» D. Both B. and C. | |
219. |
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. | |
220. |
Higher percentage of ash in coal meant for the production of metallurgical grade coke ___________________? |
A. | Decreases the hardness of coke |
B. | Decreases the abrasion resistance of coke |
C. | Causes brittleness in steel |
D. | None of these |
Answer» E. | |
221. |
Higher fuel combustion efficiency cannot 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 | |
222. |
Higher efficiency in the combustion of solid fuel cannot be achieved by________________? |
A. | Proper fuel preparation |
B. | Keeping the flue gas exhaust temperature very high |
C. | Adopting efficient-fuel firing technique & equipment |
D. | Supplying correct quantity of combustion air |
Answer» C. Adopting efficient-fuel firing technique & equipment | |
223. |
High temperature in gasification of coal favours________________? |
A. | High production of CO2 |
B. | Low production of CO2 |
C. | High production of CO |
D. | Both B. and C. |
Answer» E. | |
224. |
High temperature carbonisation of coal takes place at _______________ °C? |
A. | 2000 |
B. | 600 |
C. | 1100 |
D. | 1600 |
Answer» D. 1600 | |
225. |
High temperature carbonisation of coal produces__________________? |
A. | Inferior coke compared to low temperature carbonisation |
B. | Less of gases compared to liquid products |
C. | Large quantity of tar compared to low temperature carbonisation |
D. | None of these |
Answer» E. | |
226. |
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. | |
227. |
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 | |
228. |
High pressure coal gasification is employed in ________________ process? |
A. | Lurgi |
B. | Kopper-Totzek |
C. | Winkler |
D. | None of these |
Answer» B. Kopper-Totzek | |
229. |
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 | |
230. |
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 | |
231. |
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 | |
232. |
High amount of sulphur and phosphorous in coke causes ____________________ ? |
A. | Decrease in its calorific value |
B. | Increase in its strength |
C. | Brittleness of steel made by using it |
D. | None of these |
Answer» D. None of these | |
233. |
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 | |
234. |
Heat penetration rate in narrow coke ovens in high temperature carbonisation of coal is around ______________ cm/hr? |
A. | 2.5 |
B. | 0.5 |
C. | 10 |
D. | 20 |
Answer» B. 0.5 | |
235. |
_____________ has the widest inflammability limit (explosion limit) of all the gases? |
A. | Hydrogen |
B. | Carbon monoxide |
C. | Acetylene |
D. | Methane |
Answer» D. Methane | |
236. |
Hard pitch is used for making_____________________? |
A. | Pulverised fuel |
B. | Perfumes |
C. | Insecticides |
D. | Plastics |
Answer» B. Perfumes | |
237. |
Hard coke is manufactured from___________________? |
A. | Lignite |
B. | Bituminous coal |
C. | Semi-anthracite |
D. | Anthracite |
Answer» C. Semi-anthracite | |
238. |
Gross & net calorific value is the same for___________________? |
A. | Blast furnace gas |
B. | Coke oven gas |
C. | L.D. converter gas |
D. | None of these |
Answer» D. None of these | |
239. |
Gross heating value of coal is ______________ the net heating value? |
A. | Higher than |
B. | Lower than |
C. | Same as |
D. | None of these |
Answer» B. Lower than | |
240. |
Gross calorific value will be equal to the net calorific value for __________________? |
A. | H2 |
B. | C2H2 |
C. | CO |
D. | C2H6 |
Answer» D. C2H6 | |
241. |
Gross and net calorific value of a fuel will be the same__________________? |
A. | If its ash content is zero |
B. | If its carbon content is very low |
C. | If its hydrogen/hydrogen compound content is zero |
D. | Under no circumstances |
Answer» D. Under no circumstances | |
242. |
Grindability index of a coal is 100. It implies that the ___________________? |
A. | Coal can be pulverised with great difficulty |
B. | Coal can’t be pulverised |
C. | Coal can be easily pulverised |
D. | Power consumption in grinding the coal will be very high |
Answer» D. Power consumption in grinding the coal will be very high | |
243. |
Gray King Assay and Swelling Index of a coal is a measure of its ____________________? |
A. | Swelling characteristics |
B. | Abradability |
C. | Agglutinating properties |
D. | Resistance to impact breakage |
Answer» B. Abradability | |
244. |
Gobar gas is produced by the _______________ of ‘gobar’ (cow dung) ? |
A. | Hydrolysis |
B. | Fermentation |
C. | Oxidation |
D. | Dehydration |
Answer» C. Oxidation | |
245. |
Gobar gas is produced by the ______________ of cow dung? |
A. | Fermentation |
B. | Oxidation |
C. | Hydrogenation |
D. | None of these |
Answer» B. Oxidation | |
246. |
Gobar gas constitutes mainly of___________________? |
A. | CH4 & CO2 |
B. | CO & CO2 |
C. | CH4 & N2 |
D. | CO & N2 |
Answer» B. CO & CO2 | |
247. |
Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are normally carried out at about _____________ °C? |
A. | 400-500 |
B. | 900-1000 |
C. | 1400-1500 |
D. | 1700-1800 |
Answer» C. 1400-1500 | |
248. |
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 | |
249. |
Fussain _____________________? |
A. | Is friable, charcoal like substance |
B. | Has highest fixed carbon and lowest volatile matter content of all the four banded components of coal |
C. | Is non-coking, but when blended with highly coking coal, controls its swelling and produces high strength coke on carbonisation |
D. | All A., B. and C. |
Answer» E. | |
250. |
Fusion point of coal ash increases with increase in its ____________ content? |
A. | Iron sulphate |
B. | Iron silicate |
C. | Lime and magnesia |
D. | All A., B. and C. |
Answer» E. | |