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)

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)
by

1 Answer

Answer :

(C) Both (A) and (B)
by

Related questions

Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) Burning the fuel with theoretically required amount of pure oxygen results in attainment of maximum adiabatic flame temperature (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Description : Pick out the wrong statement. (A) Theoretical flame temperature is the temperature attained by the products of combustion, when the fuel is burned without loss or gain of heat (B) ... flame temperature (D) Adiabatic flame temperatures of actual combustions are always less than the maximum values

Last Answer : (C) Burning the fuel with excess pure oxygen results in maximum theoretical flame temperature

Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature (C) Heat release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)

Description : Coke oven gas is a better fuel than blast furnace gas, because of its higher (A) Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity) (B) Adiabatic flame temperature ... release rate (thus requiring smaller combustion chamber) (D) All (A), (B) and (C)

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

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)

Description : 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)

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

Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Description : Preheating of combustion air is done to (A) Increase the adiabatic flame temperature (B) Increase the calorific value of the fuel (C) Complete the combustion of fuel (D) Reduce its requirement for effecting the complete combustion

Last Answer : (A) Increase the adiabatic flame temperature

A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Description : A fuel with high heat release rate will (A) Require smaller combustion chamber (B) Have high calorific value (C) Have high adiabatic flame temperature (D) None of these

Last Answer : (A) Require smaller combustion chamber

For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will (A) Increase (B) Decrease (C) Increase or decrease depending on the fuel type (D) Not change

Description : For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will (A) Increase (B) Decrease (C) Increase or decrease depending on the fuel type (D) Not change

Last Answer : (B) Decrease

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

A glass chimney stops an oil lamp from smoking because: A. It increases the supply of oxygen to the flame by convection B. The heat produced ensures complete C. Both to these (Answer) D. Neither of these

Description : A glass chimney stops an oil lamp from smoking because: A. It increases the supply of oxygen to the flame by convection B. The heat produced ensures complete C. Both to these (Answer) D. Neither of these

Last Answer : C. Both to these (Answer)

Oxygen enrichment of combustion air does not result in increase of the (A) Flame temperature (B) Oxygen in the flue gas (C) Stack loss (D) Heat transfer rate in the furnace

Description : Oxygen enrichment of combustion air does not result in increase of the (A) Flame temperature (B) Oxygen in the flue gas (C) Stack loss (D) Heat transfer rate in the furnace

Last Answer : (B) Oxygen in the flue gas

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

Description : 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

Last Answer : (D) May increase or decrease; depends on the quantity of products of combustion

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

Description : 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

Last Answer : (A) Lower than

The maximum adiabatic flame temperature in air as compared to that in pure oxygen is (A) Much lower (B) Much higher (C) Same (D) Either lower or higher, depends on the type of fuel

Description : The maximum adiabatic flame temperature in air as compared to that in pure oxygen is (A) Much lower (B) Much higher (C) Same (D) Either lower or higher, depends on the type of fuel

Last Answer : (A) Much lower

Deficiency of combustion air during combustion of a gaseous fuel (A) Lengthens the flame (B) Causes heat loss of fuel by its partial combustion (C) Both (A) & (B) (D) Shortens the flame

Description : Deficiency of combustion air during combustion of a gaseous fuel (A) Lengthens the flame (B) Causes heat loss of fuel by its partial combustion (C) Both (A) & (B) (D) Shortens the flame

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

The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always (A) 1 (B) < 1 (C) > 1 (D) Unpredictable

Description : The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always (A) 1 (B) < 1 (C) > 1 (D) Unpredictable

Last Answer : (B) < 1

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

The main function of a muffle in the muffle furnace is to (A) Protect the charge from the effects of the products of combustion (B) Smooth out temperature inequalities on the combustion side of the muffle wall (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The main function of a muffle in the muffle furnace is to (A) Protect the charge from the effects of the products of combustion (B) Smooth out temperature inequalities on the combustion side of the muffle wall (C) Both (A) & (B) (D) Neither (A) nor (B)

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

During combustion of a gaseous fuel, the presence of a non-luminous flame is an indication of the (A) Incomplete combustion (B) Complete combustion (C) High oxygen in flue gas (D) None of these

Description : During combustion of a gaseous fuel, the presence of a non-luminous flame is an indication of the (A) Incomplete combustion (B) Complete combustion (C) High oxygen in flue gas (D) None of these

Last Answer : (B) Complete combustion

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)

The principle applied in liquefaction of gases is (A) Adiabatic expansion (B) Joule-Thomson effect (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Adiabatic compression of a saturated water vapour makes it (A) Supersaturated (B) Superheated (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Adiabatic compression of a saturated water vapour makes it (A) Supersaturated (B) Superheated (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : B) Superheated

he gas law (PV = RT) is true for an __________ change. (A) Isothermal (B) Adiabatic (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : he gas law (PV = RT) is true for an __________ change. (A) Isothermal (B) Adiabatic (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Work done may be calculated by the expression ∫ p dA for __________ processes. (A) Non-flow reversible (B) Adiabatic (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Work done may be calculated by the expression ∫ p dA for __________ processes. (A) Non-flow reversible (B) Adiabatic (C) Both (A) and (B) (D) Neither (A) nor (B)

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

For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because (A) Water has a high latent heat of evaporation (B) Lewis number is close to unity (C) They are always equal under all circumstances

Description : For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because (A) Water has a high latent heat of evaporation (B) Lewis number is close to unity (C) They are always equal under all circumstances

Last Answer : (A) Water has a high latent heat of evaporation

Combustion of fuel in a furnace with oxygen enriched air results in higher (A) Flue gas volume (B) Flame temperature (C) Fuel consumption (D) Stack loss

Description : Combustion of fuel in a furnace with oxygen enriched air results in higher (A) Flue gas volume (B) Flame temperature (C) Fuel consumption (D) Stack loss

Last Answer : (B) Flame temperature

Presence of nitrogen in combustion air does not reduce the (A) Amount of heat liberated (B) Flame temperature (C) Flue gas temperature (D) Any of the above

Description : Presence of nitrogen in combustion air does not reduce the (A) Amount of heat liberated (B) Flame temperature (C) Flue gas temperature (D) Any of the above

Last Answer : (A) Amount of heat liberated

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

Description : 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

Last Answer : (A) Calorific value of the fuel

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 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)

When repairing a fracture of a lower complete denture, which statement is correct: A. Self curing will distort the denture B. Cold curing will not be strong enough because of small area of attachment C. There is a possibility of occlusal disharmony

Description : When repairing a fracture of a lower complete denture, which statement is correct: A. Self curing will distort the denture B. Cold curing will not be strong enough because of small area of attachment C. There is a possibility of occlusal disharmony

Last Answer : C. There is a possibility of occlusal disharmony

Prime coking coal is always blended with medium or non- coking coal before carbonisation (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)

Description : Prime coking coal is always blended with medium or non- coking coal before carbonisation (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)

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

The maximum adiabatic flame temperature is attained, when the fuel is burnt with (A) Theoretically required amount of air(B) More than theoretically required amount of air(C) Less than theoretically required amount of air(D) Theoretically required amount of oxygen

Description : The maximum adiabatic flame temperature is attained, when the fuel is burnt with (A) Theoretically required amount of air (B) More than theoretically required amount of air (C) Less than theoretically required amount of air (D) Theoretically required amount of oxygen

Last Answer : (D) Theoretically required amount of oxygen

Refrigeration cycle (A) Violates second law of thermodynamics (B) Involves transfer of heat from low temperature to high temperature (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Refrigeration cycle (A) Violates second law of thermodynamics (B) Involves transfer of heat from low temperature to high temperature (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (B) Involves transfer of heat from low temperature to high temperature

Pick out the undesirable property for a solvent meant for dewaxing of lube oil. (A) Complete miscibility with oil (B) High solubility of wax in the solvent (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Pick out the undesirable property for a solvent meant for dewaxing of lube oil. (A) Complete miscibility with oil (B) High solubility of wax in the solvent (C) Both (A) and (B) (D) Neither (A) nor (B)

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

Preheating of __________ the flame temperature. (A) The gaseous fuel before combustion decreases (B) Combustion air decreases (C) Either the fuel or the air or both, increases (D) Either the fuel or the air does not affect

Description : Preheating of __________ the flame temperature. (A) The gaseous fuel before combustion decreases (B) Combustion air decreases (C) Either the fuel or the air or both, increases (D) Either the fuel or the air does not affect

Last Answer : (C) Either the fuel or the air or both, increases

Breathing loss" on storage of gasoline occurs due to the (A) Presence of unsaturated air (B) Fluctuation of ambient temperature during day and night (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Breathing loss" on storage of gasoline occurs due to the (A) Presence of unsaturated air (B) Fluctuation of ambient temperature during day and night (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (B) Fluctuation of ambient temperature during day and night

Use of excess of combustion air in the combustion of fuels results in (A) Heat losses (B) Long flame (C) Condensation of water vapour from the fuel gas (D) None of these

Description : Use of excess of combustion air in the combustion of fuels results in (A) Heat losses (B) Long flame (C) Condensation of water vapour from the fuel gas (D) None of these

Last Answer : (A) Heat losses

Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle  A. combustion is at constant volume  B. expansion and compression are isentropic  C. maximum temperature is higher  D. heat rejection is lower

Description : Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle  A. combustion is at constant volume  B. expansion and compression are isentropic  C. maximum temperature is higher  D. heat rejection is lower

Last Answer : Answer: D

The heat capacities for the ideal gas state depend upon the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The heat capacities for the ideal gas state depend upon the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Temperature

Advantages of fluidised bed combustion are (A) Reduced NOx formation in flue gas (B) Lower furnace operating temperature (C) High heat transfer rate (D) All (A), (B) & (C)

Description : Advantages of fluidised bed combustion are (A) Reduced NOx formation in flue gas (B) Lower furnace operating temperature (C) High heat transfer rate (D) All (A), (B) & (C)

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

Factor of safety against sliding of a slope, is the ratio of (A) Actual cohesion to that required to maintain stability of slope (B) Shear strength to shear stress along the surface (C) Neither (a) nor (b) (D) Both (a) and (b)

Description : Factor of safety against sliding of a slope, is the ratio of (A) Actual cohesion to that required to maintain stability of slope (B) Shear strength to shear stress along the surface (C) Neither (a) nor (b) (D) Both (a) and (b)

Last Answer : Answer: Option D

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 because of the color of the flame, when it is burnt (D) Gaseous fuels require less percentage of excess air for combustion as compared to liquid fuels

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

Which of the following is/are correct with reference to Abstract class and interface ? (a) A class can inherit only one Abstract class but may inherit several interfaces. (b) An Abstract class can provide complete and default code but an interface has no code. Codes : (A) (a) is true (B) (b) is true (C) Both (a) and (b) are true (D) Neither (a) nor (b) is true

Description : Which of the following is/are correct with reference to Abstract class and interface ? (a) A class can inherit only one Abstract class but may inherit several interfaces. (b) An Abstract class can provide complete and default ... true (C) Both (a) and (b) are true (D) Neither (a) nor (b) is true

Last Answer : Answer: C

Higher vapour pressure of gasoline indicates(A) Low flash point(B) High breathing loss(C) Both (A) and (B)(D) Neither (A) nor (B

Description : Higher vapour pressure of gasoline indicates (A) Low flash point (B) High breathing loss (C) Both (A) and (B) (D) Neither (A) nor (B

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

In case of liquid petrofuels, momentary combustion is observed at its (A) Flash point (B) Preheating temperature corresponding to viscosity of 25 centistokes (C) Flame temperature (D) Fire point

Description : In case of liquid petrofuels, momentary combustion is observed at its (A) Flash point (B) Preheating temperature corresponding to viscosity of 25 centistokes (C) Flame temperature (D) Fire point

Last Answer : (A) Flash point

Advantages of use of preheated combustion air are (A) Saving in fuel consumption (B) Reduction in scale losses (C) Increase in flame temperature (D) All (A), (B) and (C)

Description : Advantages of use of preheated combustion air are (A) Saving in fuel consumption (B) Reduction in scale losses (C) Increase in flame temperature (D) All (A), (B) and (C)

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

Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Description : Which of the following advantages is not associated with the use of preheated air for combustion of a fuel in the furnace? (A) Increase in calorific value of the fuel (B) Increase in flame temperature (C) Reduction in scale losses (D) Saving in fuel consumption

Last Answer : (A) Increase in calorific value of the fuel

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

Description : 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

Last Answer : (A) Lengthens the flame

Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Description : Use of preheated air for combustion of fuel in the furnace, increases the (A) Scale losses of the furnace stock (B) Calorific value of the fuel (C) Flame temperature (D) None of these

Last Answer : (C) Flame temperature

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

With increase in temperature, the leaching rate increases because of the (A) Increased diffusivity (B) Decreased viscosity of liquid (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : With increase in temperature, the leaching rate increases because of the (A) Increased diffusivity (B) Decreased viscosity of liquid (C) Both (A) and (B) (D) Neither (A) nor (B)

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