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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.
| 1001. |
Range of compressibility co-efficient of the commercial compressible cake obtained in filtration operation is |
| A. | 0.01 to 0.1 |
| B. | 0.1 to 0.3 |
| C. | 0.2 to 0.8 |
| D. | 0.2 to 0.4 |
| Answer» D. 0.2 to 0.4 | |
| 1002. |
Highly viscous liquids & pastes are agitated by |
| A. | propellers |
| B. | turbine agitators |
| C. | multiple blade paddles |
| D. | none of these |
| Answer» D. none of these | |
| 1003. |
Which of the following mineral dressing operations is termed as 'comminution'? |
| A. | Panning |
| B. | Spiralling |
| C. | Tabling |
| D. | None of these |
| Answer» E. | |
| 1004. |
Fractional conversion __________ with increase in pressure for ammonia synthesis reaction i.e., N2 + 3H2 2NH3. |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | unpredictable from the data |
| Answer» B. decreases | |
| 1005. |
The reason why a catalyst increases the rate of reaction is that, it |
| A. | decreases the energy barrier for reaction. |
| B. | increases the activation energy. |
| C. | decreases the molecular collision diameter. |
| D. | none of these. |
| Answer» B. increases the activation energy. | |
| 1006. |
A first order irreversible reaction, A B is carried out separately in a constant volume as well as in a variable volume reactor for a particular period. It signifies that __________ in the two reactors. |
| A. | both conversion as well as concentration are same |
| B. | conversion in both will be the same but concentrations will be different |
| C. | both the conversion as well as concentrations will be different |
| D. | none of these. |
| Answer» C. both the conversion as well as concentrations will be different | |
| 1007. |
The rate constant of a chemical reaction decreases by decreasing the |
| A. | pressure |
| B. | concentration of reactants |
| C. | temperature |
| D. | duration of reaction |
| Answer» D. duration of reaction | |
| 1008. |
Reaction rate equation for the reaction, . If S at is present in large excess, what is the order of this reaction? |
| A. | zero |
| B. | one |
| C. | two |
| D. | three |
| Answer» C. two | |
| 1009. |
'If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the |
| A. | pressure |
| B. | temperature |
| C. | both (a) & (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) & (b) | |
| 1010. |
For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption. |
| A. | physical |
| B. | chemical |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) and (b) | |
| 1011. |
The dimensions of rate constant for reaction 3A B are (l/gm mole)/min. Therefore the reaction order is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 1012. |
If the time required to complete a definite fraction of reaction varies inversely as the concentration of the reactants, then the order of reaction is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 1013. |
For a zero order chemical reaction, the |
| A. | half life period is directly proportion to the initial concentration of the reac-tants. |
| B. | plot of products concentration with time is a straight line through the origin. |
| C. | products concentration increases linerarly with time. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1014. |
BET apparatus |
| A. | measures the catalyst surface area directly. |
| B. | operates at very high pressure. |
| C. | is made entirely of stainless steel. |
| D. | none of these. |
| Answer» E. | |
| 1015. |
Radioactive decay follows __________ order kinetics. |
| A. | first |
| B. | second |
| C. | third |
| D. | zero. |
| Answer» B. second | |
| 1016. |
The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. |
| A. | activation |
| B. | potential |
| C. | binding |
| D. | threshold |
| Answer» B. potential | |
| 1017. |
The increase in the rate of reaction with temperature is due to |
| A. | increase in the number of effective collisions. |
| B. | decrease in activation energy. |
| C. | increase in the average kinetic energy of the reacting molecules. |
| D. | none of these. |
| Answer» C. increase in the average kinetic energy of the reacting molecules. | |
| 1018. |
A catalyst loses its activity due to |
| A. | loss in surface area of the active component. |
| B. | agglomeration of metal particles caused by thermal sintering of the solid surface. |
| C. | covering of the catalytic active sites by a foregin substance. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1019. |
'N' plug flow reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for __________ order reactions. |
| A. | first |
| B. | second |
| C. | third |
| D. | any |
| Answer» E. | |
| 1020. |
Specific rate constant for a second order reaction |
| A. | is independent of temperature. |
| B. | varies with temperature. |
| C. | depends on the nature of the reactants. |
| D. | both (b) and (c). |
| Answer» E. | |
| 1021. |
The rate constant of a chemical reaction increases by 100 times when the temperature is increased from 400 K to 500 K. Assuming transition state theory is valid, the value of E/R is |
| A. | 8987 K |
| B. | 9210 K |
| C. | 8764 K |
| D. | 8621 K |
| Answer» C. 8764 K | |
| 1022. |
For a heterogeneous catalytic reaction |
| A. | free energy of activation is lowered in the presence of catalyst, which remains unchanged at the end of reaction. |
| B. | a relatively small amount of catalyst can cause the conversion of large amount of reactants which does not mean that catalyst concentration is important. |
| C. | the catalyst does not form an intermediate complex with the reactant. |
| D. | the surface of the catalyst does not play an important role during reaction. |
| Answer» B. a relatively small amount of catalyst can cause the conversion of large amount of reactants which does not mean that catalyst concentration is important. | |
| 1023. |
Which of the following is the most suitable for very high pressure gas phase reaction ? |
| A. | Batch reactor |
| B. | Tubular flow reactor |
| C. | Stirred tank reactor |
| D. | Fluidised bed reactor |
| Answer» C. Stirred tank reactor | |
| 1024. |
What is the order of a chemical reaction, , if the rate of formation of 'C', increases by a factor of 2.82 on doubling the concentration of 'A' and increases by a factor of 9 on trebling the concentration of 'B'? |
| A. | 7/2 |
| B. | 7/4 |
| C. | 5/2 |
| D. | 5/4 |
| Answer» B. 7/4 | |
| 1025. |
For high conversion in a highly exothermic solid catalysed reaction, use a __________ bed reactor. |
| A. | fixed |
| B. | fluidised bed reactor followed by a fixed |
| C. | fixed bed reactor followed by a fluidised |
| D. | fluidised |
| Answer» C. fixed bed reactor followed by a fluidised | |
| 1026. |
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. | |
| 1027. |
Which of the following is the most reactive (as regards the formation of CO + H2 from C + H2O) ? |
| A. | Blast furnace coke |
| B. | Low temperature coke |
| C. | Anthracite coal |
| D. | Sub-bituminous coal |
| Answer» C. Anthracite coal | |
| 1028. |
Calorific value of coal middling generated in coal washeries during washing of coal may be around __________ Kcal/kg. |
| A. | 1000 |
| B. | 4000 |
| C. | 6000 |
| D. | 8000 |
| Answer» C. 6000 | |
| 1029. |
Flue gas discharge velocity through chimney of a big thermal power plant may be around __________ m/sec. |
| A. | 0.5 |
| B. | 10 |
| C. | 50 |
| D. | 500 |
| Answer» C. 50 | |
| 1030. |
Which of the following is used for making the explosive 'TNT' ? |
| A. | Benzol |
| B. | Toluene |
| C. | Pyridine |
| D. | Cerosote |
| Answer» C. Pyridine | |
| 1031. |
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. | |
| 1032. |
Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is __________ percent. |
| A. | < 37% |
| B. | >71% |
| C. | in between 37 & 71% |
| D. | none of these |
| Answer» D. none of these | |
| 1033. |
Prime coking coal is always blended with medium or non- coking coal before ear-bonisation |
| A. | to check against its excessive swelling during heating, which may exert high pressure and damage coke oven walls. |
| B. | because, it alone produces unreactive coke. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1034. |
Actual flame temperature is always lower than the adiabatic flame temperature, because there is |
| A. | no possibility of obtaining complete combustion at high temperature. |
| B. | always loss of heat from the flame. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1035. |
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) | |
| 1036. |
Which of the following gaseous fuels has the lowest calorific value ? |
| A. | Gobar gas |
| B. | Refinery gas |
| C. | Converter gas |
| D. | Blast furnace gas |
| Answer» E. | |
| 1037. |
Which of the following is not a by-product recovered in a high temperature coal carbonisation plant ? |
| A. | Benzol |
| B. | Pitch-cresosote mixture (PCM) |
| C. | Napthalene |
| D. | Ethylene |
| Answer» E. | |
| 1038. |
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 | |
| 1039. |
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. | |
| 1040. |
Combustion of pulverised coal as compared to that of lump coal |
| A. | develops a non-luminous flame. |
| B. | develops a low temperature flame. |
| C. | can be done with less excess air. |
| D. | provides a lower rate of heat release. |
| Answer» D. provides a lower rate of heat release. | |
| 1041. |
'Wobbe index' is a characteristic of |
| A. | solid fuels |
| B. | gaseous fuels |
| C. | liquid fuels |
| D. | fat coals |
| Answer» C. liquid fuels | |
| 1042. |
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. | |
| 1043. |
Presence of free moisture in coal during its high temperature carbonisation |
| A. | reduces the coking time. |
| B. | protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls. |
| C. | increases the loss of fine coal dust from the ovens when charging. |
| D. | none of these. |
| Answer» C. increases the loss of fine coal dust from the ovens when charging. | |
| 1044. |
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. | |
| 1045. |
Laboratory gas is obtained by the cracking of |
| A. | gasoline |
| B. | diesel |
| C. | fuel oil |
| D. | kerosene |
| Answer» E. | |
| 1046. |
Carbon Content by weight in air dried wood may be about __________ percent. |
| A. | 10 |
| B. | 25 |
| C. | 50 |
| D. | 80 |
| Answer» D. 80 | |
| 1047. |
Which of the following accentuates clinker-ing trouble on furnace grate burning coal ? |
| A. | Low reactivity of carbonised residue containing high proportions of iron & sulphur. |
| B. | Low forced draught and fuel bed temperature. |
| C. | Thick fire bed and preheated primary air. |
| D. | All (a), (b) and (c). |
| Answer» E. | |
| 1048. |
Natural draught produced by a chimney depends upon the |
| A. | density of the chimney gases. |
| B. | height of the chimney. |
| C. | both (a) and (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1049. |
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 | |
| 1050. |
Stack heat losses can be minimised by |
| A. | controlling the excess air. |
| B. | oxygen enrichment of combustion air. |
| C. | using low c.v. fuels. |
| D. | maintaining proper draft in the furnace. |
| Answer» B. oxygen enrichment of combustion air. | |