Rate of low temperature oxidation of coal due to bad storage conditions (A) Decreases with increase in surface area (B) Does not vary with increase in surface area (C) Is more for low volatile coal compared to high volatile coal (D) Is accelerated by storage in large heaps with small surface to volume ratio

Rate of low temperature oxidation of coal due to bad storage conditions
(A) Decreases with increase in surface area
(B) Does not vary with increase in surface area
(C) Is more for low volatile coal compared to high volatile coal
(D) Is accelerated by storage in large heaps with small surface to volume
ratio
by

1 Answer

Answer :

(D) Is accelerated by storage in large heaps with small surface to volume
ratio
by

Related questions

Spontaneous combustion of coal on storage results due to(A) Inadequate ventilation (B) Low temperature oxidation (C) Storage in large heaps with small surface to volume ratio (D) All (A), (B) and (C)

Description : Spontaneous combustion of coal on storage results due to (A) Inadequate ventilation (B) Low temperature oxidation (C) Storage in large heaps with small surface to volume ratio (D) All (A), (B) and (C)

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

Low temperature oxidation of coal is accelerated by the (A) Storage in large heaps (B) Storage in compressed piles (C) Absence of porous or friable particles (D) All (A), (B) and (C)

Description : Low temperature oxidation of coal is accelerated by the (A) Storage in large heaps (B) Storage in compressed piles (C) Absence of porous or friable particles (D) All (A), (B) and (C)

Last Answer : (A) Storage in large heaps

To avoid fire by spontaneous combustion of coal due to its low temperature oxidation, it should be stored in (A) Shallow and small piles (B) Fine sizes without the presence of any lump (C) Closed space without any ventilation facility (D) Large heaps with small surface to volume ratio

Description : To avoid fire by spontaneous combustion of coal due to its low temperature oxidation, it should be stored in (A) Shallow and small piles (B) Fine sizes without the presence of any lump (C) Closed space without any ventilation facility (D) Large heaps with small surface to volume ratio

Last Answer : (A) Shallow and small piles

Low temperature oxidation and spontaneous combustion of freshly mined coal is accentuated, if (A) It contains large amount of volatile matter (B) It is stored in tall heaps (C) Smaller fines are stored in large quantity (D) All (A), (B) and (C)

Description : Low temperature oxidation and spontaneous combustion of freshly mined coal is accentuated, if (A) It contains large amount of volatile matter (B) It is stored in tall heaps (C) Smaller fines are stored in large quantity (D) All (A), (B) and (C)

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

A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon (A) Is less liable to spontaneous combustion on storage (B) Is more difficult to ignite and produces a shorter flame (C) Requires smaller combustion space and less secondary air (D) None of these

Description : A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon (A) Is less liable to spontaneous combustion on storage (B) ... a shorter flame (C) Requires smaller combustion space and less secondary air (D) None of these

Last Answer : (D) None of these

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

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

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

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

Pick out the correct statement.(A) Angle of repose is always greater than the angle of slide (B) A hopper is a small bin with a sloping bottom (C) A silo is a short height vessel of very large diameter used for the storage of high volatile matter coal (D) Pine oil is used as a 'modifying agent' (for activating or depressing the adsorption of filming agents) in froth floatation process

Description : Pick out the correct statement. (A) Angle of repose is always greater than the angle of slide (B) A hopper is a small bin with a sloping bottom (C) A silo is a short height ... used as a 'modifying agent' (for activating or depressing the adsorption of filming agents) in froth floatation process

Last Answer : (B) A hopper is a small bin with a sloping bottom

Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile matter coals are more suitable for making pulverised fuel (C) Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Description : Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile ... and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Last Answer : (D) None of these

Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation (B) Film co-efficient for vaporisation decreases as a result of vapor binding (C) In industrial practice, sub-cooling of condensate is required, when thecondensate is a volatile liquid and is to be transferred for storage(D) Overall heat transfer co-efficient in a heat exchanger is controlled by thevalue of the film co-efficient, which is higher

Description : Pick out the wrong statement. (A) The condensing film co-efficient is about 3 times lower for vertical condenser as compared to the equivalent horizontal condenser for identical situation ( ... in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Last Answer : (D) Overall heat transfer co-efficient in a heat exchanger is controlled by the value of the film co-efficient, which is higher

Clausius-Clapeyron Equation gives accurate result, when the (A) Vapour pressure is relatively low and the temperature does not vary over wide limits (B) Vapour obeys the ideal gas law and the latent heat of vaporisation is constant (C) Volume in the liquid state is negligible compared with that in the vapour state (D) All (A), (B) and (C)

Description : Clausius-Clapeyron Equation gives accurate result, when the (A) Vapour pressure is relatively low and the temperature does not vary over wide limits (B) Vapour obeys the ideal gas law and the latent heat of ... is negligible compared with that in the vapour state (D) All (A), (B) and (C)

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

Pick out the wrong statement. (A) Angle of repose of coal increases with its increasing size (B) Specific gravity of coal increases with its increasing maturity (C) Refractive index and reflectance of coal increases with the increasing rank of coal (D) Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

Description : Pick out the wrong statement. (A) Angle of repose of coal increases with its increasing size (B) Specific gravity of coal increases with its increasing maturity (C) Refractive index and reflectance of ... of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

Last Answer : (D) Specific heat of coal decreases with increases in the volatile matter and decrease in the C/H ratio of coal

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

Description : 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

Last Answer : (D) Ignition temperature

Low temperature oxidation of coal during storage does not decrease its (A) Oxygen content (B) Caking power (C) Calorific value (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

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

Description : 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

Last Answer : (D) None of these

A coal containing high amount of volatile matter will have (A) Low ignition temperature (B) Very little ash content (C) High fusion point of its ash (D) Low adiabatic flame temperature

Description : A coal containing high amount of volatile matter will have (A) Low ignition temperature (B) Very little ash content (C) High fusion point of its ash (D) Low adiabatic flame temperature

Last Answer : (A) Low ignition temperature

Coke compared to the coal from which it has been made, contains (A) Less volatile matter (B) More carbon (C) Greater percentage of ash (D) All (A), (B) and (C)

Description : Coke compared to the coal from which it has been made, contains (A) Less volatile matter (B) More carbon (C) Greater percentage of ash (D) All (A), (B) and (C)

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

With the increase in depth, the hydrostatic pressure in an un-accelerated incompressible fluid (in a constant gravitational field) (A) Decreases (B) Increases linearly (C) Increases exponentially (D) Remain constant

Description : With the increase in depth, the hydrostatic pressure in an un-accelerated incompressible fluid (in a constant gravitational field) (A) Decreases (B) Increases linearly (C) Increases exponentially (D) Remain constant

Last Answer : (B) Increases linearly

A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co￾efficient for air will vary in the ratio of (A) 2 (B) 2 0.8 (C) 2 0.2 (D) 2 0.5

Description : A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co￾efficient for air will vary in the ratio of (A) 2 (B) 2 0.8 (C) 2 0.2 (D) 2 0.5

Last Answer : (B) 2 0.8

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)

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)

Viscosity of a polymer solution or melt (A) Decreases with increase in molecular weight (B) Decreases with increase in temperature (C) Increases with increase in temperature (D) Does not vary with temperature rise

Description : Viscosity of a polymer solution or melt (A) Decreases with increase in molecular weight (B) Decreases with increase in temperature (C) Increases with increase in temperature (D) Does not vary with temperature rise

Last Answer : (C) Increases with increase in temperature

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

Description : 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

Last Answer : (C) Temperature maintained is 700°C

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 volatile matter percentage in coal is called its 'fuel ratio' (D) Calorific value of natural gas is more than that of LPG

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

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

Description : 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

Last Answer : (C) Can be done with less excess ai

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 monoxidecontent increases(C) Calorific value of the coke oven gas decreases due to cracking ofhydrocarbons which is not compensated by increase in CO & H2 content(D) All (A), (B) and (C)

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)

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

Description : 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

Last Answer : (A) High volatile matter

Fat' coal means a coal having (A) Low calorific value (B) High volatile matter (C) Low ash content

Description : Fat' coal means a coal having (A) Low calorific value (B) High volatile matter (C) Low ash content

Last Answer : (B) High volatile matter

With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Description : With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Last Answer : (A) Increases

Aluminium alloy is one of the most suitable materials of construction for aircrafts mainly due to its (A) High strength to weight ratio (B) Low temperature strength properties (C) Its ability to be cast, rolled, forged & stamped (D) High strength and corrosion & oxidation-resistance at elevated temperature

Description : Aluminium alloy is one of the most suitable materials of construction for aircrafts mainly due to its (A) High strength to weight ratio (B) Low temperature strength properties (C) Its ability ... rolled, forged & stamped (D) High strength and corrosion & oxidation-resistance at elevated temperature

Last Answer : (A) High strength to weight ratio

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

Description : 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

Last Answer : (B) Protects the volatile products from pyrolysis (cracking) in the presence of hot coke and hot oven walls

Coal containing large quantity of __________ are difficult to wash. (A) Ash (B) Inherent mineral matter (C) Free impurities (D) Volatile matter

Description : Coal containing large quantity of __________ are difficult to wash. (A) Ash (B) Inherent mineral matter (C) Free impurities (D) Volatile matter

Last Answer : (B) Inherent mineral matter

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

Description : 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

Last Answer : (A) Fast & high

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

Description : 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

Last Answer : (D) Aromatic content of tar produced is more

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)

Description : 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)

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

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

Description : 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

Last Answer : (B) Aliphatic tar is produced

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

Description : 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

Last Answer : (C) H2 content in the coke oven gas is more

The fuel ratio of a coal is (A) The ratio of its percentage of fixed carbon to that of volatile matter (B) Helpful in estimation of its rank (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : The fuel ratio of a coal is (A) The ratio of its percentage of fixed carbon to that of volatile matter (B) Helpful in estimation of its rank (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has (A) Higher calorific value (B) Lower hydrogen content (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Coke oven gas produced by high temperature carbonisation of coal (as compared to that produced by low temperature carbonisation), has (A) Higher calorific value (B) Lower hydrogen content (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (D) Neither (A) nor (B)

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

Description : 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

Last Answer : (A) Difference in gross & net calorific value of the coke oven gas

High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation(B) Less of gases compared to liquid products(C) Larger quantity of tar compared to low temperature carbonisation(D) None of these

Description : High temperature carbonisation of coal produces (A) Inferior coke compared to low temperature carbonisation (B) Less of gases compared to liquid products (C) Larger quantity of tar compared to low temperature carbonisation (D) None of these

Last Answer : (D) None of these

The main factor for the accelerated growth of population in India is– (1) Low birth rate and low death rate (2) A high birth rate and a falling death rate (3) A rising birth rate and a rising death rate (4) A high birth rate and a high death rate

Description : The main factor for the accelerated growth of population in India is– (1) Low birth rate and low death rate (2) A high birth rate and a falling death rate (3) A rising birth rate and a rising death rate (4) A high birth rate and a high death rate

Last Answer : (2) A high birth rate and a falling death rate Explanation: Owing to improvement in health care and advance-ment of technology the death rate has been declined over the years.

Which of the following may account for the small size of the cells? A- .The rate of diffusion B- The surface area/volume ratio C- The number of mRNAs that can be produced by the nucleus D- All of the above

Description : Which of the following may account for the small size of the cells? A- .The rate of diffusion B- The surface area/volume ratio C- The number of mRNAs that can be produced by the nucleus D- All of the above

Last Answer : All of the above

When Marrion divided 24 oranges into 3 heaps in the ratio 4 to 5 to 3 how many oranges were in each heap?

Description : When Marrion divided 24 oranges into 3 heaps in the ratio 4 to 5 to 3 how many oranges were in each heap?

Last Answer : There are 8, 10 and 6.

In batch distillation with constant reflux, overhead product composition __________ with time. (A) Increases (B) Decreases (C) Does not vary (D) May increase on decrease, depends on the system

Description : In batch distillation with constant reflux, overhead product composition __________ with time. (A) Increases (B) Decreases (C) Does not vary (D) May increase on decrease, depends on the system

Last Answer : (B) Decreases

In area meter (e.g., Rotameter), with increase in the fluid flow rate, the (A) Pressure drop increases linearly (B) Pressure drop is almost constant (C) Area through which fluid flows does not vary (D) None of these

Description : In area meter (e.g., Rotameter), with increase in the fluid flow rate, the (A) Pressure drop increases linearly (B) Pressure drop is almost constant (C) Area through which fluid flows does not vary (D) None of these

Last Answer : (B) Pressure drop is almost constant

Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the (A) Surrounding temperature (B) Average temperature of the fin (C) Temperature of the fin end (D) Constant temperature equal to that of the base

Description : Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer ... (C) Temperature of the fin end (D) Constant temperature equal to that of the base

Last Answer : (D) Constant temperature equal to that of the base

Coal is heated in absence of air for 7 minutes at a temperature of about __________ °C, during its volatile matter determination for proximateanalysis.(A) 550(B) 750(C) 950(D) 1150

Description : Coal is heated in absence of air for 7 minutes at a temperature of about __________ °C, during its volatile matter determination for proximateanalysis. (A) 550 (B) 750 (C) 950 (D) 1150

Last Answer : (C) 950

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

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

Pick out the wrong statement. (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment (B) The emissivity of a surface increases with increase in surface roughness (C) The emissivity of a polished surface is quite low (D) The emissivity of a non-metallic surface decreases with increase in the temperature

Description : Pick out the wrong statement. (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment (B) The emissivity of a surface increases with increase in surface roughness ... quite low (D) The emissivity of a non-metallic surface decreases with increase in the temperature

Last Answer : (A) The emissivity of a surface decreases, if it gets corroded by atmospheric environment