Pick out the correct statement.
(A) Oxygen content decreases from lignite to bituminous coal as the
coalification increases
(B) The less the oxygen content, better is the coal, as it reduces the calorific
value
(C) With increase in oxygen content, moisture holding capacity of coal
increases and the caking power decreases
(D) All (A), (B) and (C)

1 Answer

Answer :

(D) All (A), (B) and (C)

Related questions

Description : With increase in moisture content of coal, its (A) Calorific value increases (B) Caking properties diminish (C) Swelling during carbonisation becomes excessive (D) None of these

Last Answer : (B) Caking properties diminish

Description : 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)

Last Answer : (C) Both (A) & (B)

Description : Low temperature oxidation of stored coal results in the (A) Decrease in its caking power & calorific value (B) Decrease in its carbon & hydrogen content (C) Increase in its oxygen content (D) All (A), (B) and (A)

Last Answer : (D) All (A), (B) and (A)

Description : 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

Last Answer : (C) Friability & oxygen content

Description : With increase in moisture content of coal, its (A) Calorific value increases sometimes (B) Bulk density always decreases (C) Clinkering tendency during combustion increases (D) None of these

Last Answer : (D) None of these

Description : Low temperature oxidation of coal during storage does not decrease its (A) Oxygen content (B) Caking power (C) Calorific value (D) None of these

Last Answer : (D) None of these

Description : Low temperature oxidation of coal resulting from bad storage conditions does not decrease its (A) Caking power (B) Calorific value (C) Hydrogen content (D) Oxygen content

Last Answer : (D) Oxygen content

Description : Which of the following has the highest calorific value? (A) Lignite (B) Sub-bituminous coal (C) Anthracite (D) Peat

Last Answer : (C) Anthracite

Description : As the equilibrium moisture content of the coal increases, its (A) Calorific value increases (B) Swelling number decreases (C) Swelling number increases (D) Bulk density decreases

Last Answer : (B) Swelling number decreases

Description : 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

Last Answer : (B) Ratio of fixed carbon to volatile matter increases

Description : A coal having higher volatile matter content will necessarily have lower (A) Ash fusion temperature (B) Calorific value (C) Ignition temperature (D) Caking index

Last Answer : (C) Ignition temperature

Description : With increase in the temperature of carbonisation of coal (A) Hydrogen content of coke oven gas increases due to cracking ofhydrocarbons (B) Methane content in the coke oven gas decreases and carbon monoxide content increases ( ... compensated by increase in CO & H2 content (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Which of the following coals has the highest calorific value? (A) Lignite (B) Sub-bituminous (C) Anthracite (D) Peat

Last Answer : (C) Anthracite

Description : Coalification means the (A) Process of conversion of lignite into anthracite (B) Underground gasification of coal (C) Complete combustion of coal (D) Direct hydrogenation of coa

Last Answer : (A) Process of conversion of lignite into anthracite

Description : 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

Last Answer : (A) Volatile matter content increases

Description : Pick out the wrong statement. (A) Percentage of ash in coke produced from medium coking coal is more than that in coal (B) The calorific value (kcal/Nm3 ) of coke oven gas reduces on ... plants in India at Talcher (Orissa) and Ramagundam (A.P) employ Kopper-Totzek process of coal gasification

Last Answer : (C) Ash is normally removed as 'fly-ash' in Kopper-Totzek process of coal gasification

Description : Which one of the following lists four type of coal, arranged in the increasing order of their carbon content? (a) Peat, Lignite, Bituminous, Anthracite (b) Peat, Bituminous, Lignite, Anthracite (c) Lignite, Peat, Bituminous, Anthracite (d) Peat, Anthracite, Lignite, Bituminous

Last Answer : Ans: (a)

Description : The weathering index of a coal (A) Gives an idea of the fusion temperature of ash (B) Is related to its calorific value (C) Is a measure of its size stability, when stored & exposed to weather (D) Is a measure of its caking tendency

Last Answer : (C) Is a measure of its size stability, when stored & exposed to weather

Description : __________ of the coal is the basis for Seylor's coal classification. (A) Proximate analysis (B) Ultimate analysis (C) Caking index (D) Calorific value

Last Answer : (B) Ultimate analysis

Description : 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 conten

Last Answer : (A) Caking capacity

Description : Out of the following fuels, the difference between the net and gross calorific value is maximum in case of (A) Pitch (B) Fuel oil (C) Blast furnace gas (D) Bituminous coal

Last Answer : (B) Fuel oil

Description : Washing of coal decreases its (A) Caking index (B) Mineral matter content (C) Ash content (D) Both (B) and (C)

Last Answer : (B) Mineral matter content

Description : Calorific value of bituminous coal may be around __________ Kcal/kg. (A) 500 (B) 1500 (C) 6500 (D) 20000

Last Answer : (C) 6500

Description : Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction (A) Decreases with decrease of thickness of the flakes (B) Increases with the increasing flake size ... considerably with the rise of temperature (D) Decreases as the moisture content of flakes increases

Last Answer : (D) Decreases as the moisture content of flakes increases

Description : Pick out the wrong statement. (A) High concentration of oxygen in flue gas means high stack loss (B) Gaseous fuels require the least % excess air for complete combustion (C) The ratio of fixed carbon to ... coal is called its 'fuel ratio' (D) Calorific value of natural gas is more than that of LPG

Last Answer : (D) Calorific value of natural gas is more than that of LPG

Description : Pick out the wrong statement. (A) Strongly caking coal should not be used in the Lurgi gasifier (B) Acetylene gas cannot be used for illumination purpose (C) Water gas is called blue gas ... is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

Last Answer : (B) Acetylene gas cannot be used for illumination purpose

Description : The most matured coal out of the following is (A) Lignite (B) Semi-anthracite (C) Sub-bituminous (D) Bituminous

Last Answer : (B) Semi-anthracite

Description : Which of the following can be made into briquettes without the use of a binder? (A) Lignite (B) Bituminous coal (C) Anthracite coal (D) None of these

Last Answer : (A) Lignite

Description : The difference between total carbon and fixed carbon of coal will be minimum in case of (A) Lignite (B) Bituminous coal (C) Anthracite (D) High temperature coke (V.M < 0.5%)

Last Answer : (D) High temperature coke (V.M < 0.5%)

Description : Hard coke is manufactured from (A) Lignite (B) Bituminous coal (C) Semi-anthracite (D) Anthracite

Last Answer : (B) Bituminous coal

Description : Which is the most matured coal? (A) Lignite (B) Bituminous (C) Semi-anthracite (D) Anthracite

Last Answer : (D) Anthracite

Description : Pitch (a product of coal tar distillation) is always mixed with creosote oil, when it is to be burnt in a burner, because (A) Its calorific value is very less (B) Tar neutralises the residual acids ... for its transportation through pipelines at economic pressure drop (D) All (A), (B) and (C)

Last Answer : (C) It reduces viscosity and imparts fluidity for its transportation through pipelines at economic pressure drop

Description : Pick up the correct statement from the following: (A) The dry density reduces by addition of water after attaining optimum moisture content (B) The line joining the peak of three moisture content graphs ... be compacted to a very high density as compared to fine grained soils (D) All the above

Last Answer : Answer: Option D

Description : Pick up the correct statement from the following: (A) A highly absorptive aggregate reduces the workability of concrete considerably (B) The specific gravity of aggregate is important for the determination ... and porosity of an aggregate influence the property of the concrete (D) All the above

Last Answer : Answer: Option D

Description : 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)

Last Answer : (D) All (A), (B) and (C)

Description : Pick up the correct statement from the following: (A) Adding 5% to 6% of moisture content by weight, increases the volume of dry sand from 18% to 38% (B) The bulking of fine sand is ... the percentage content of moisture exceeds 10%, increase in bulk of sand starts increasing (D) All the above

Last Answer : Answer: Option D

Description : Which of the following is considered as superior quality of coal ? (A) Bituminous coal (B) Peat (C) Lignite (D) Coke.

Last Answer : Ans: A

Description : The highest grade and best quality coal is – (1) Lignite (2) Peat (3) Bituminous (4) Anthracite

Last Answer : (4) Anthracite Explanation: Anthracite is usually considered to be the highest grade of coal and is actually considered to be metamorphic. Compared to other coals it is much harder, has a glassy ... with few impurities. It is largely used for heating domestically as it burns with little smoke.

Description : Which one of the following is known as the 'brown coal'? (1) Anthracite (2) Bituminous (3) Coke (4) Lignite

Last Answer : (4) Lignite Explanation: Lignite, often referred to as brown coal, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal. It has ... 66%, and an ash content ranging from 6% to 19% compared with 6% to 12% for bituminous coal.

Description : Which one of the following is known as the ‘brown coal’? (1) Anthracite (2) Bituminous (3) Coke (4) Lignite

Last Answer : (4) Lignite Explanation: Lignite, often referred to as brown coal, is a soft brown fuel with characteristics that put it somewhere between coal and peat. It is considered the lowest rank of coal. It has a carbon content of around 2530%.

Description : Which is the highest quality of hard coal? (1) Anthracite (2) Bituminous (3) Lignite (4) Peat

Last Answer : (1) Anthracite Explanation: Anthracite is the highest rank of coal. It is the most metamorphosed type of coal, in which the carbon content is between 92.1% and 98%. Anthracite coal generally has ... heating value per ton on a mineralmatter-free basis. Anthracite is often referred to as hard coal.

Description : Highest percentage of carbon is found in which form of coal? (1) Anthracite (2) Bituminous (3) Peat (4) Lignite

Last Answer : (1) Anthracite Explanation: Anthracite is the highest rank of coal since it has a carbon content of over 87% on a dry ash-free basis. Anthracite coal generally has the highest heating value per ton on a mineral-matter-free basis. It has a bright luster and breaks with a semi-conchoidal. fracture.

Description : Which one of the following is not coal variety? (1) Lignite (2) Bituminous (3) Dolomite (4) Peat

Last Answer : (3) Dolomite Explanation: Dolomite is a common rockforming mineral. It is a calcium magnesium carbonate with a chemical composition of CaMg(CO3)2. It is the primary component of the sedimentary ... known as dolomitic marble. Dolomite is used in the Pidgeon process for the production of magnesium.

Description : Which of the following type of coal has the lowest proportion of volatile matter? (1) Lignite (2) Peat (3) Bituminous (4) Anthracite

Last Answer : (4) Anthracite Explanation: Anthracite has the lowest proportion of volatile matter. Volatile matter in coal refers to the components of coal, except for moisture, which are liberated at ... hydrocarbons and some sulfur. The volatile matter of coal is determined under rigidly controlled standards.

Description : Which one of the following types of coal contains a higher percentage of carbon than the rest? (1) Bituminous coal (2) Lignite (3) Peat (4) Anthracite

Last Answer : (4) Anthracite Explanation: Anthracite is thecoal that gives the most energy and the least pollution (it produces lots of CO2). It is the ideal fuel for power station.

Description : Which of the following is considered as superior quality of coal? (A) Bituminous coal (B) Peat (C) Lignite (D) Coke.

Last Answer : Bituminous coal

Description : Which coal is considered a metamorphic rock? w) anthracite coal x) bituminous coal y) lignite coal z) all of these

Last Answer : ANSWER: W -- ANTHRACITE

Description : In terms of quality, what is the highest ranked coal? w) peat x) bituminous y) anthracite z) lignite

Last Answer : ANSWER: Y -- ANTHRACITE

Description : Among the following, the substance that is considered to be the earliest stage in coal formation is: w) sub-bituminous x) bituminous y) anthracite z) lignite

Last Answer : ANSWER: Z -- LIGNITE