MCQOPTIONS
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MCQOPTIONS
This section includes 1154 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1101. |
Which of the following is a primary fuel ? |
| A. | Blast furnace coke |
| B. | Gasoline |
| C. | Natural gas |
| D. | Wood charcoal |
| Answer» D. Wood charcoal | |
| 1102. |
Naphthalene is used for making |
| A. | insecticides (e.g. moth balls). |
| B. | unsaturated polyesters. |
| C. | drug intermediates e.g. β-naphthol. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1103. |
The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always |
| A. | 1 |
| B. | <1 |
| C. | > 1 |
| D. | unpredicatable |
| Answer» C. > 1 | |
| 1104. |
The bright glow of a combustion process is the characteristic of __________ temperature oxidation of coal. |
| A. | fast & high |
| B. | slow & low |
| C. | slow & high |
| D. | fast & slow |
| Answer» B. slow & low | |
| 1105. |
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. | |
| 1106. |
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. | |
| 1107. |
The temperature at which plastic layer formation takes place during carbonisation of coal varies from __________ °C. |
| A. | 100 to 150 |
| B. | 350 to 450 |
| C. | 550 to 650 |
| D. | 700 to 850 |
| Answer» C. 550 to 650 | |
| 1108. |
Coke oven gas consists mainly of |
| A. | H2, & CH4 |
| B. | CO, & CO2 |
| C. | H2, & CO |
| D. | CH4, & CO |
| Answer» B. CO, & CO2 | |
| 1109. |
The gasification reaction represented by, C + H2O = CO + H2, is |
| A. | exothermic |
| B. | endothermic |
| C. | catalytic |
| D. | autocatalytic |
| Answer» C. catalytic | |
| 1110. |
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature ? |
| A. | Calorific value of the fuel. |
| B. | Flame temperature achieved. |
| C. | Speed of combustion of fuel. |
| D. | Heat transfer rate to the stock in the furnace. |
| Answer» B. Flame temperature achieved. | |
| 1111. |
A coal with high ash content is undesirable, as |
| A. | it is abrasive to the coal pulveriser (ie.g. ball mill) and the combustion chamber. |
| B. | the ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the ash. |
| C. | the ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes thereby reducing the heat transfer. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1112. |
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 | |
| 1113. |
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. | |
| 1114. |
With increase in calorific value of fuels, their adiabatic flame temperatures |
| A. | increase |
| B. | decrease |
| C. | remain unchanged |
| D. | may increase or decrease ; depends on the quantity of products of combustion |
| Answer» E. | |
| 1115. |
Pensky-Marten apparatus is used for those oils, whose flash points are __________ °F. |
| A. | <120 |
| B. | >120 |
| C. | <90 |
| D. | 90-110 |
| Answer» C. <90 | |
| 1116. |
Which of the following has the highest flame velocity ? |
| A. | H2 |
| B. | CO |
| C. | CH4 |
| D. | C2H6 |
| Answer» B. CO | |
| 1117. |
Mineral matter content (M) and ash content (A) in coal are approximately related as |
| A. | M = 1.1A |
| B. | M = A |
| C. | M = 1.5A |
| D. | M = 2A |
| Answer» B. M = A | |
| 1118. |
Yield of blast furnace gas is about __________ Nm3 /ton of pig iron. |
| A. | 300 |
| B. | 2000 |
| C. | 5000 |
| D. | 10000 |
| Answer» C. 5000 | |
| 1119. |
Which of the following fuels is generally not used in thermal power plant boiler firing? |
| A. | Furnace oil, light diesel oil and tar/PCM. |
| B. | Pulverised coking coal. |
| C. | Coal middling from washeries. |
| D. | B.F. gas, coke oven gas and L.D. converter gas. |
| Answer» C. Coal middling from washeries. | |
| 1120. |
Laboratory gas is obtained by the cracking of |
| A. | gasoline |
| B. | diesel |
| C. | fuel oil |
| D. | kerosene |
| Answer» E. | |
| 1121. |
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. | |
| 1122. |
Orsat apparatus |
| A. | gives flue gas analysis on dry basis. |
| B. | determines N2 in flue gas indirectly. |
| C. | can't determine CO in flue gas, if it is < 0.2%. |
| D. | all (a), (b) & (c). |
| Answer» E. | |
| 1123. |
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. | |
| 1124. |
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. | |
| 1125. |
Supply of excess air for complete combustion of fuel is necessitated to facilitate |
| A. | its thorough mixing with air. |
| B. | attainment of chemical equilibrium. |
| C. | attainment of high temperature. |
| D. | none of these. |
| Answer» B. attainment of chemical equilibrium. | |
| 1126. |
Ratio of primary air to secondary air increases with increase in the rank of coal, because the |
| A. | high rank coals have higher amount of volatile matter. |
| B. | ratio of fixed carbon to volatile matter increases. |
| C. | oxygen content progressively decreases. |
| D. | calorific value of the coal increases. |
| Answer» C. oxygen content progressively decreases. | |
| 1127. |
Which of the following is not a by-product fuel? |
| A. | Producer gas |
| B. | Blast furnace gas |
| C. | Coke oven gas |
| D. | Refinery gas |
| Answer» B. Blast furnace gas | |
| 1128. |
Which of the following is not a binder for coal briquetting ? |
| A. | Coal tar |
| B. | Bitumen |
| C. | Molasses |
| D. | None of these |
| Answer» E. | |
| 1129. |
By-products recovery process from coal carbonisation is termed as direct, indirect and semi direct process depending upon the method of recovery of |
| A. | tar |
| B. | benzol |
| C. | ammonia |
| D. | none of these |
| Answer» D. none of these | |
| 1130. |
Coke oven gas is stripped of its H2S and mercaptans content by |
| A. | absorption in wash oil. |
| B. | adsorption on bog iron bed. |
| C. | bubbling it through dilute sulphuric acid. |
| D. | adsorption on silica gel. |
| Answer» C. bubbling it through dilute sulphuric acid. | |
| 1131. |
During the carbonisation of coal |
| A. | all tar is evolved at < 600°C. |
| B. | evolution of H2 and formation of methane and aromatics occur at > 700°C. |
| C. | hard semi-coke starts shrinking at 600°C. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1132. |
Coking time in a commercial high temperature coal carbonisation plant is about __________ hours. |
| A. | 6 |
| B. | 18 |
| C. | 28 |
| D. | 36 |
| Answer» C. 28 | |
| 1133. |
For every 10% increase in the excess air; the fuel consumption increases by __________ percent. |
| A. | 0.1 |
| B. | 2 |
| C. | 5 |
| D. | 10 |
| Answer» B. 2 | |
| 1134. |
__________ 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 | |
| 1135. |
Which of the following is not used as a binder in coal briquetting ? |
| A. | Tar |
| B. | Molasses |
| C. | Pitch |
| D. | Line |
| Answer» E. | |
| 1136. |
Low temperature carbonisation |
| A. | is mainly for producing the smokeless domestic coke. |
| B. | is meant for the production of 'metallurgical coke'. |
| C. | produces higher quantity of gas than high temperature carbonisation. |
| D. | produces less quantity of tar than high temperature carbonisation. |
| Answer» B. is meant for the production of 'metallurgical coke'. | |
| 1137. |
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. | |
| 1138. |
A coal containing very high percentage of durain is called __________ coal. |
| A. | bright |
| B. | splint |
| C. | non-banded |
| D. | boghead |
| Answer» C. non-banded | |
| 1139. |
Gross and net calorific value of a fuel will be the same |
| A. | if its ash content is zero. |
| B. | ifits carbon content is very low. |
| C. | if its hydrogen/hydrogen compound content is zero. |
| D. | under no circumstances. |
| Answer» D. under no circumstances. | |
| 1140. |
Coals used for the generation of producer gas should have |
| A. | high caking index. |
| B. | low fusion point of ash. |
| C. | high volatile matter content. |
| D. | very low ash content (8-10%). |
| Answer» D. very low ash content (8-10%). | |
| 1141. |
A coal having high amount of volatile matter |
| A. | would require smaller combustion chamber. |
| B. | produces very little of tar and gas on carbonisation. |
| C. | ignites easily and burns with long smoky flame. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1142. |
The reaction, C + CO2 2CO, taking place during coal gasification is called the __________ reaction. |
| A. | Neumann reversal |
| B. | shift conversion |
| C. | Boudouard |
| D. | reduction |
| Answer» D. reduction | |
| 1143. |
Adiabatic flame temperature of a fuel is dependent on the initial temperature of |
| A. | fuel |
| B. | air |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1144. |
Sulphur in metallurgical coal |
| A. | contributes to its heating value. |
| B. | affects the quality of steel produced as cracks develop on the surface while rolling the steel. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1145. |
Calorific value of coke oven gas is around __________ Kcal/Nm3. |
| A. | 900 |
| B. | 4200 |
| C. | 7500 |
| D. | 2000 |
| Answer» C. 7500 | |
| 1146. |
Fuel gases containing hydrocarbons (ie.g. coke oven gas) are not preheated before burning, mainly because |
| A. | the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot. |
| B. | it reduces its calorific value tremendously. |
| C. | it reduces its flame temperature tremendously. |
| D. | there are chances of explosion during preheating. |
| Answer» B. it reduces its calorific value tremendously. | |
| 1147. |
During combustion of gaseous fuels, deficiency of air |
| A. | lengthens the flame. |
| B. | tends to shorten the flame. |
| C. | does not affect the flame length. |
| D. | increases the flame temperature. |
| Answer» B. tends to shorten the flame. | |
| 1148. |
When incomplete combustion loss is high, the flue gas analysis shows large amount of |
| A. | CO2 |
| B. | CO |
| C. | O2 |
| D. | C |
| Answer» C. O2 | |
| 1149. |
The calorific value of natural gas is about __________ kcal/Nm3. |
| A. | 10, 000 |
| B. | 2500 |
| C. | 25, 000 |
| D. | 35, 000 |
| Answer» B. 2500 | |
| 1150. |
The maximum adiabatic flame temperature in air is __________ the maximum flame temperature in pure oxygen. |
| A. | lower than |
| B. | higher than |
| C. | same as |
| D. | not related to |
| Answer» B. higher than | |