The lowest temperature, at which a solid fuel produces enough vapors
to support continuous combustion, is called
(A) Fire point
(B) Smoke point
(C) Burning temperature
(D) Kindling temperature

1 Answer

Answer :

(C) Burning temperature

Related questions

Description : The engine produces dark black smoke due to a) Burning of oil b) Due of incomplete combustion c) Due to moisture in fuel d) None of these Ans. b

Last Answer : ans b

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

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

Description : Pick out the wrong statement. (A) LPG is also used as fuel for automobiles & small furnaces and for cutting & welding of metals (B) The minimum temperature, at which a petroleum oil vapor catches ... about 30-50 Nm3 of gas (D) Maximum yield of naphthalene is obtained on distillation of crude oil

Last Answer : (B) The minimum temperature, at which a petroleum oil vapor catches fire and continues to burn, is called its flash point

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

Description : White phosphorous is stored under water, because (A) It does not react with water (B) It is poisonous (C) Its kindling temperature in dry air is very low (D) It is unstable

Last Answer : (C) Its kindling temperature in dry air is very low

Description : are portable devices capable of estimating the combusting efficiency of furnaces, boilers, or other fossil fuel burning machines. a) Sound analyzer. c) Combustion analyzer. b) Light analyzer. d)Temperature analyzer

Last Answer : Combustion analyzer. 

Description : are portable devices capable of estimating the combusting efficiency of furnaces, boilers, or other fossil fuel burning machines. a) Sound analyzer. b) Light analyzer. c) Combustion analyzer. d) Temperature analyzer.

Last Answer : Combustion analyzer.

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)

Description : Higher efficiency in the combustion of solid fuel cannot be achieved by (A) Proper fuel preparation (B) Keeping the flue gas exhaust temperature very high (C) Adopting efficient-fuel firing technique & equipment (D) Supplying correct quantity of combustion air

Last Answer : (B) Keeping the flue gas exhaust temperature very high

Description : The optimum percentage of excess air for combustion depends upon the__________ of the fuel. (A) Type (solid, liquid or gaseous) (B) Calorific value (C) Sulphur content (D) Ignition temperature

Last Answer : (A) Type (solid, liquid or gaseous)

Description : he temperature at which solid content of fuel freeze out is called.... (a) Fire point (b) Flash point (c) Pour point (d) Cloud point

Last Answer : (a) Fire point

Description : In an operating distillation column, the (A) Vapors and liquids are at their dew point and bubble point respectively (B) Driving force for the liquid flow is its specific weight (C) Driving force for ... bottom to the top of the column (D) Highest temperature is encountered at the top of the column

Last Answer : (C) Driving force for the vapor flow is the pressure drop, as the pressure decreases gradually from the bottom to the top of the column

Description : Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby ... B) Irritation in eyes (C) Respiratory trouble (D) All (A), (B) and (C)

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

Description : Smoke is produced due to (A) Insufficient supply of combustion air and insufficient time for combustion (B) Poor quality of fuel and improper mixing of fuel & combustion air (C) Poor design & overloading of furnace (D) All (A), (B) and (C)

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

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

Description : What is the Chemical processes that causes that causes the production of ignitable vapors from solid wood?

Last Answer : Pyrolysis

Description : Why is water not suitable for putting out a petrol fire? (1) The oxygen content of water is isolated by petrol and thus it helps in burning (2) Petrol is too inflammable to be extinguished by ... very low (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns

Last Answer : (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns Explanation: Water is not effective on petrol fire because it has higher density than ... while petrol stays afloat and keeps burning. Petrochemical fires are nearly always extinguished with chemical foam.

Description : Why is water not suitable for putting out a petrol fire? (1) The oxygen content of water is isolated by petrol and thus it helps in burning (2) Petrol is too inflammable to be extinguished by ... very low (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns

Last Answer : (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns Explanation: Water is not effective on petrol fire because it has higher density than petrol as a ... extinguished with chemical foam which forms a blanket over the flames and cuts off the oxygen supply.

Description : Why is water not suitable for putting out a petrol fire ? (1) The oxygen content of water is isolated by petrol and thus it helps in burning (2) Petrol is too inflammable to be extinguished by ... very low (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns 

Last Answer : Water, being heavy, slips below petrol which thus remains in contact with air and burns

Description : Fuel' can be defined as a substance which produces heat by (A) Combustion (B) Nuclear fission (C) Nuclear fusion (D) All (A), (B) & (C)

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

Description : Smoke point of kerosene is the (A) Time after which smoking starts on burning (B) Temperature at which smoking starts (C) Maximum height of flame (in mm) without causing smoking, when burnt in a standard lamp (D) None of these

Last Answer : (B) Temperature at which smoking starts

Description : In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of (A) Use of non-preheated combustion air (B) Use of pulverised solid ... of fuel & air and infiltration of air (D) Use of excessive positive draft in the furnace

Last Answer : (C) Imperfect mixing of fuel & air and infiltration of air

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

Description : A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are ... and without total reflux (D) The top and bottom compositions correspond to the maximum enrichment available

Last Answer : (D) The top and bottom compositions correspond to the maximum enrichment available

Description : Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C. (A) 80 (B) 130 (C) 180 (D) 250

Last Answer : (B) 130

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)

Description : The main source of carbon monoxide is (1) Industrial process (2) Fuel combustion (3) Transportation (4) Solid waste disposal

Last Answer : (3) Transportation Explanation: The main source of carbon monoxide is burning of fossil fuel

Description : The main source of carbon monoxide is (1) Industrial process (2) Fuel combustion (3) Transportation (4) Solid waste disposal 

Last Answer : Transportation

Description : Presence of predominantly large quantity of aromatics (polynuclear) is not desirable in aviation fuel, because it has (A) High pour point and low smoke point (B) Low viscosity index (C) High self-ignition temperature (D) All (A), (B) and (C)

Last Answer : (B) Low viscosity index

Description : Smoke point of kerosene expresses its (A) Burning characteristics (B) Luminosity characteristics (C) Aromatic content directly (D) Lamp wick wetting characteristics

Last Answer : (A) Burning characteristics

Description : Smoke point of a good burning kerosene may be around __________ mm. (A) 0-5 (B) 20-25 (C) 60-75 (D) 100-120

Last Answer : (B) 20-25

Description : Which measurable property become constant in Water Water vapors equilibrium at constant temperature

Last Answer : Ans. Vapour pressure.

Description : ______________ is the temperature at which liquids start to boil or the temperature at which vapors begin to condense.  a. Saturation Temperature  b. Sub cooled Liquid  c. Compressed Liquid  d. Saturated Liquid

Last Answer : Saturation Temperature

Description : Which temperature for a lubricating oil will be lowest ? (A) Flash point (B) Fire point (C) Pour point (D) Boiling

Last Answer : Ans: C

Description : Which of the following statements are correct about chloroform? a. Liquid fuel b. Anaesthetic in nature c. Produces phosgene d. Fire extinguisher (1) a, b (2) a, c (3) b, c (4) d, a

Last Answer : b, c

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

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)

Description : Inside the distillation columns, the (A) Highest temperatures is near the feed plate (B) Driving force for the liquid flow is its weight (C) Vapors are not always at their dew points (D) All (A), (B) and (C)

Last Answer : (B) Driving force for the liquid flow is its weigh

Description : Which of the following processes is not an example of adsorption applied to gaseous separations? (A) Recovery of valuable solvent vapors from dilute mixture with air and ... Removal of objectionable odour and impurities from industrial gases (D) Decolouration of yellow glycerine

Last Answer : (D) Decolouration of yellow glycerine

Description :  For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd , then (A) hf = hd (B) hf > hd (C) hf < hd (D) hf could be greater or smaller than hd

Last Answer : (C) hf < hd

Description : The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor

Last Answer : (C) Some

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

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)

Description : Size of the combustion chamber of a furnace depends upon the (A) Heat release rate of the fuel (B) Preheat temperature of fuel & air (C) Method of mixing the fuel & air (D) All (A), (B) and (C)

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

Description : Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by (A) Increasing the draft in the furnace (B) Preheating the fuel gas (C) Oxygen enrichment of combustion air (D) Preheating the combustion air

Last Answer : (A) Increasing the draft in the furnace

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

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)

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

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