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

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
by

1 Answer

Answer :

(A) Fast & high
by

Related questions

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)

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

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 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)

If majority of students in your class is weak you should Options: A) Not Care About Intelligent student B) Keep Your Speed Of Teaching Fast So That Students Comprehension Level May Increase C) Keep Your Teaching Slow Which Can Also Be Helpful To Bright Students. D) Keep Your Teaching Slow Along With Some Extra Guidance To Bright People

Description : If majority of students in your class is weak you should Options: A) Not Care About Intelligent student B) Keep Your Speed Of Teaching Fast So That Students Comprehension Level May Increase C) ... Helpful To Bright Students. D) Keep Your Teaching Slow Along With Some Extra Guidance To Bright People

Last Answer : D) Keep Your Teaching Slow Along With Some Extra Guidance To Bright People

A coal containing very high percentage of durain is called __________ coal. (A) Bright (B) Splint (C) Non-banded (D) Boghead

Description : A coal containing very high percentage of durain is called __________ coal. (A) Bright (B) Splint (C) Non-banded (D) Boghead

Last Answer : (B) Splint

Two bulbs of 100w and 40w respectively are connected in series across a 230v supply which bulb will glow bright and why?

Description : Two bulbs of 100w and 40w respectively are connected in series across a 230v supply which bulb will glow bright and why?

Last Answer : A:Since two bulbs are in series they will get equal amount of electrical current but as the supply voltage is constant across the bulb(P=V^2/R).So the resistance of 40W bulb is greater and voltage across 40W is more (V=IR) so 40W bulb will glow brighter.

Two bulbs of 100w and 40w respectively connected in series across a 230v supply which bulb will glow bright and why?

Description : Two bulbs of 100w and 40w respectively connected in series across a 230v supply which bulb will glow bright and why?

Last Answer : Since two bulbs are in series they will get equal amount of electrical current but as the supply voltage is constant across the Bulb (P=V^2/R).So the resistance of 40W bulb is greater and voltage across 40W is more (V=IR) so 40W bulb will glow brighter.

Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace. (A) Low amount of excess combustion air (B) Large quantity of excess combustion air(C) Hydrocarbon fuel(D) Pulverised coal as fuel

Description : Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace. (A) Low amount of excess combustion air (B) Large quantity of excess combustion air (C) Hydrocarbon fuel (D) Pulverised coal as fuel

Last Answer : (A) Low amount of excess combustion air

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

Description : 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 ... to high volatile coal (D) Is accelerated by storage in large heaps with small surface to volume ratio

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

During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)

Description : During combustion of coal on grate, clinker formation is increased by the (A) Use of thick fire bed (B) Low fusion point of ash (< 1100° C) (C) Use of preheated primary air (D) All (A), (B) & (C)

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

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

Atmospheric corrosion of metals result from their (A) Slow oxidation (B) Fast oxidation (C) Fast hydration (D) Slow dehydration

Description : Atmospheric corrosion of metals result from their (A) Slow oxidation (B) Fast oxidation (C) Fast hydration (D) Slow dehydration

Last Answer : (A) Slow oxidation

Combustion of pulverised coal compared to the lumpy coal (A) Provides better control of furnace temperature (B) Facilitates combustion with lower excess air (C) Provides higher thermal efficiency & flame temperature (D) All (A), (B) & (C)

Description : Combustion of pulverised coal compared to the lumpy coal (A) Provides better control of furnace temperature (B) Facilitates combustion with lower excess air (C) Provides higher thermal efficiency & flame temperature (D) All (A), (B) & (C)

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

Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent. (A) 3 & 10 (B) 10 & 3 (C) 10 & 20 (D) 15 & 8

Description : Tar yield in the low temperature and high temperature carbonisation of dry coal may be respectively __________ percent. (A) 3 & 10 (B) 10 & 3 (C) 10 & 20 (D) 15 & 8

Last Answer : (B) 10 & 3

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

The advantage of firing pulverised coal in the furnace lies in the fact, that it (A) Permits the use of high ash content coal (B) Permits the use of low fusion point ash coal(C) Accelerates the burning rate and economises on fuel combustion(D) All (A), (B) and (C)

Description : The advantage of firing pulverised coal in the furnace lies in the fact, that it (A) Permits the use of high ash content coal (B) Permits the use of low fusion point ash coal (C) Accelerates the burning rate and economises on fuel combustion (D) All (A), (B) and (C)

Last Answer : (C) Accelerates the burning rate and economises on fuel combustion

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

Bright coal (A) Contains more than 90% durain (B) Contains more than 90% fussain (C) Contains mainly vitrain & clarain and is generally coking (D) Is non-coking

Description : Bright coal (A) Contains more than 90% durain (B) Contains more than 90% fussain (C) Contains mainly vitrain & clarain and is generally coking (D) Is non-coking

Last Answer : (C) Contains mainly vitrain & clarain and is generally coking

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

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

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

Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. (A) Coal ash (B) Potassium cyanide (C) Ortho-xylene (D) None of these

Description : Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. (A) Coal ash (B) Potassium cyanide (C) Ortho-xylene (D) None of these

Last Answer : (B) Potassium cyanide

__________ the exhaust gas is an indication of the incomplete combustion of fuel. (A) Low temperature of (B) High temperature of (C) High % of CO in (D) High % of CO2in

Description : __________ the exhaust gas is an indication of the incomplete combustion of fuel. (A) Low temperature of (B) High temperature of (C) High % of CO in (D) High % of CO2in

Last Answer : (C) High % of CO in

__________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C. (A) Veneering (B) Galvanising (C) Electroplating (D) Calorising

Description : __________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C. (A) Veneering (B) Galvanising (C) Electroplating (D) Calorising

Last Answer : (D) Calorising

Which of the following is not applicable to fluidised bed combustion of coal? (A) It cannot burn low grade coal (B) It achieves higher fuel combustion efficiency (C) Less heat transfer surface area is required in boilers (D) None of these

Description : Which of the following is not applicable to fluidised bed combustion of coal? (A) It cannot burn low grade coal (B) It achieves higher fuel combustion efficiency (C) Less heat transfer surface area is required in boilers (D) None of these

Last Answer : (A) It cannot burn low grade coal

The excess air required for the combustion of pulverised coal is of the order of about __________ percent. (A) 5 (B) 15 (C) 30 (D) 45

Description : The excess air required for the combustion of pulverised coal is of the order of about __________ percent. (A) 5 (B) 15 (C) 30 (D) 45

Last Answer : (B) 15

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

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

Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the (A) Requirement of large volume combustion chamber (B) Risk of explosion (C) Chances of clinker formation (D) Incomplete combustion of coal

Description : Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the (A) ... chamber (B) Risk of explosion (C) Chances of clinker formation (D) Incomplete combustion of coal

Last Answer : (B) Risk of explosion

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

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

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

Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

Description : Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by (A) Preheating the combustion air (B) Oxygen enrichment of combustion air (C) Preheating the fuel gas (D) All (A), (B) & (C)

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

The public school is __________ (A) a comprehensive school for bright children in which the tuition is free. (B) a specialized school for talented children in which the tuition fee is quite low. (C) a private school for privileged children in which the tuition fee is very high. (D) a common boarding school for all children.

Description : The public school is __________ (A) a comprehensive school for bright children in which the tuition is free. (B) a specialized school for talented children in which the tuition fee is quite low. (C) a ... children in which the tuition fee is very high. (D) a common boarding school for all children.

Last Answer : (C) a private school for privileged children in which the tuition fee is very high.

Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

Description : Which of the following accentuates clinkering troubles on furnace grate burning coal? (A) Low reactivity of carbonised residue containing high proportion of iron & sulphur (B) Low forced draft & fuel bed temperature (C) Thick firebed and preheated primary air (D) All (A), (B) and (C)

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

Which of the following accentuates clinkering 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)

Description : Which of the following accentuates clinkering 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)

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

The reactions with low activation energy are (A) Always spontaneous (B) Slow (C) Fast (D) Non-spontaneous

Description : The reactions with low activation energy are (A) Always spontaneous (B) Slow (C) Fast (D) Non-spontaneous

Last Answer : (C) Fast

When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2 , it is called the __________ of coal. (A) Carbonisation (B) Oxidation (C) Coalification (D) Gasification

Description : When steam is passed over coal resulting in the endothermic reaction represent by, C + H2O = CO + H2 , it is called the __________ of coal. (A) Carbonisation (B) Oxidation (C) Coalification (D) Gasification

Last Answer : (D) Gasification

Exposure of a photographic plate to produce a latent image is an example of __________ reaction. (A) Very slow (B) Very fast (C) Photochemical (D) Both (B) and (C)

Description : Exposure of a photographic plate to produce a latent image is an example of __________ reaction. (A) Very slow (B) Very fast (C) Photochemical (D) Both (B) and (C)

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

Which of the following petrological constitutes is responsible for bright and lustrous black band of bituminous coal? (A) Vitrain (B) Clarain (C) Durain

Description : Which of the following petrological constitutes is responsible for bright and lustrous black band of bituminous coal? (A) Vitrain (B) Clarain (C) Durain

Last Answer : (A) Vitrain

Low NOx Combustion Technology Regulation in Japan for Coal Firing Boiler has reduced from 400 ppm to____ a. 100ppm b. 200ppm c. 300ppm d. 400ppm

Description : Low NOx Combustion Technology Regulation in Japan for Coal Firing Boiler has reduced from 400 ppm to____ a. 100ppm b. 200ppm c. 300ppm d. 400ppm

Last Answer : Ans:- b. 200ppm

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)

Description : 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)

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

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)

Description : 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)

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

Producer gas containing least amount of tar is produced by the (A) Partial combustion of coal (B) Partial combustion of large size (< 50 mm) coke (C) High pressure gasification of coal (e.g. in Lurgi gasifier) (D) Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)

Description : Producer gas containing least amount of tar is produced by the (A) Partial combustion of coal (B) Partial combustion of large size (< 50 mm) coke (C) High pressure gasification of coal (e.g. in Lurgi gasifier) (D) Atmospheric pressure gasification of coal (e.g., in Kopper-Totzek gasifier)

Last Answer : (B) Partial combustion of large size (< 50 mm) coke

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

Use of pulverised coal in boiler furnace provides (A) High calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace walls

Description : Use of pulverised coal in boiler furnace provides (A) High calorific value (B) Better combustion (C) Smokeless burning (D) Less erosion on furnace walls

Last Answer : (B) Better combustion

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

Description : 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

Last Answer : (A) Low(A) Low

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)

Description : 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)

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

Incomplete combustion of a fuel is characterised by the high __________ in the flue gas. (A) Smoke (B) Temperature (C) Oxygen (D) Carbon monoxide

Description : Incomplete combustion of a fuel is characterised by the high __________ in the flue gas. (A) Smoke (B) Temperature (C) Oxygen (D) Carbon monoxide

Last Answer : (D) Carbon monoxide