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)

1 Answer

Answer :

(B) Low viscosity index

Related questions

Description : Paraffins are desirable in lubricating oil, as it has got high (A) Viscosity (B) Viscosity index (C) Smoke point (D) Pour poin

Last Answer : (C) Smoke point

Description : Which one is preferred for aircraft engine? (A) High viscosity index lube oil (B) Low viscosity index lube oil (C) High freezing point aviation fuel (D) None of these

Last Answer : (A) High viscosity index lube oil

Description : Cetane number of a diesel fuel is the measure of its (A) Ignition delay (B) Smoke point (C) Viscosity (D) Oxidation stability

Last Answer : (A) Ignition delay

Description : Explain the following properties i) Pour point ii) Viscosity iii) Ignition quality iv) Fire point

Last Answer : i. Pour point: Pour point is the temperature below which the entire mass of fuel, solid or liquid together, freeze and thus cause flow of fuel impossible. Pour point is usually 5 to 10 °C below ... is the temperature at which the flash will sustain itself as a steady flame for at least five seconds.

Description : Aromatics have the highest __________ of all the hydrocarbons of same carbon atoms. (A) Smoke point (B) Octane number (C) Cetane number (D) Viscosity

Last Answer : (B) Octane number

Description : A good lubricant should have high (A) Viscosity index (B) Volatility (C) Pour point (D) None of these

Last Answer : (A) Viscosity index

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. all of the above

Last Answer : ANSWER d. all of the above

Description : The probability of knocking in diesel engines is increased by a. High self-ignition temperature. b. Low volatility. c. High viscosity. d. All of the above

Last Answer : ANSWER d. all of the above

Description : Presence of aromatics in (A) Diesel increases its cetane number (B) Kerosene increases its smoke point (C) Petrol increases its octane number (D) All (A), (B) and (C)

Last Answer : (C) Petrol increases its octane number

Description : High aniline point of diesel indicates that, it (A) Is highly aromatic (B) Has a large ignition delay (C) Is highly paraffinic (D) Has a low diesel index

Last Answer : (C) Is highly paraffinic

Description : Good quality kerosene should have (A) Low smoke point (B) High smoke point (C) High aromatics content (D) Low paraffins content

Last Answer : (B) High smoke point

Description : Fuel oil is subjected to visbreaking to reduce its (A) Pour point (B) Viscosity (C) Pressure drop on pumping (D) All (A), (B) and (C

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

Description : A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the (A) Presence of large ... fuel (C) High sulphur content in the fuel (D) Lack of thorough mixing of fuel with air

Last Answer : (D) Lack of thorough mixing of fuel with air

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 : Extractor temperature is maintained at -20°C in Edeleanu process to reduce the __________ of kerosene. (A) Smoke point (B) Paraffins (C) Aromatics (D) Naphthenes

Last Answer : (B) Paraffins

Description : . Pick out the wrong statement. (A) Multigrade lubricating oils have high viscosity index (B) Paraffinic oil has very high viscosity index (C) Naphthenic oil has very low viscosity index (D) High viscosity index means a large change in viscosity with change in temperature

Last Answer : (D) High viscosity index means a large change in viscosity with change in temperature

Description : The tendency of knocking in CI engine reduces by (a) High self ignition temperature of fuel (b) Decrease in jacket water temperature (c) Injection of fuel just before TDC (d) Decrease in injection pressure

Last Answer : Ans :c

Description : High aniline point of a petrofuel (say diesel) indicates that (A) It is highly aromatic in nature (B) It is highly paraffinic in nature (C) It has a very low diesel index (D) Its ignition quality is very poor

Last Answer : (B) It is highly paraffinic in nature

Description : Pick out the wrong statement. (A) Lower boiling paraffins have higher octane number than higher paraffins (B) Dehydrogenation of naphthenes to aromatics is a desirable reaction in reforming ... is dearomatised kerosene (D) Catalyst used in catalytic reforming is platinum on silica-alumina base

Last Answer : (C) The most ideal feedstock for thermal reforming is dearomatised kerosene

Description : Which is the most desirable component of a good quality kerosene? (A) i-paraffins (B) Aromatics (C) n-paraffins (D) Naphthenes

Last Answer : (C) n-paraffins

Description : Which of the following is desirable in diesel and kerosene but is undesirable in gasoline? (A) Aromatics (B) Mercaptans (C) Paraffins (D) Naphthenic acid

Last Answer : (A) Aromatics

Description : Which of the following is desirable in petrol (gasoline) but undesirable in kerosene? (A) Paraffins (B) Aromatics (C) Mercaptans

Last Answer : (C) Mercaptans

Description : Hydrofining is the most recent and effective method for the (A) Removal of sulphur (B) Improvement of smoke point (C) Reduction of breathing loss (D) Improvement of viscosity index

Last Answer : (A) Removal of sulphur

Description : Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent (A) Dental cavities (B) Scale formation (C) Water-borne disease (D) Corrosion

Last Answer : (A) Dental cavities

Description : Bag filter design is predominantly dependent on gas temperature, as it affects the gas density & viscosity and the selection of filtering material. The pressure drop in a bag filter is (A) Inversely proportional to ... the gas (C) Proportional to the pressure of the gas (D) Both (B) and (C)

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

Description : Smoke point of a test sample of kerosene is found to be 15 mm. On removal of __________ from it, the smoke point rises to 25 mm. (A) n-paraffins (B) Olefins (C) Aromatics (D) None of these

Last Answer : (C) Aromatics

Description : Pick out the correct statement. (A) Paraffins have higher octane number than corresponding iso-paraffin (B) Paraffins have lower smoke point than aromatics

Last Answer : (B) Paraffins have lower smoke point than aromatics

Description : Octane number of gasoline is a measure of its (A) Resistance to knock (B) Ignition delay (C) Ignition temperature (D) Smoke point

Last Answer : (A) Resistance to knock

Description : The self-ignition temperature of diesel oil compared to petrol is a. higher b. lower c. same d. depends on the quality of fuel

Last Answer : ANSWER a. higher

Description : Cetane number is a measure of a. ignition quality b. addition in fuel c. calorific value of fuel d. viscosity of the fuel

Last Answer : ANSWER a. ignition quality

Description : Priming in a distillation column (A) Results from very low gas velocity (B) Is desirable from point efficiency consideration (C) Is characterised by the presence of foam throughout the space between trays (D) Reduces the overall pressure drop

Last Answer : (C) Is characterised by the presence of foam throughout the space between trays

Description : Viscosity index of a lubricating oil (A) Is the measure of its flash point (B) Is the measure of variation of viscosity with temperature (C) Should be low (D) None of these

Last Answer : (B) Is the measure of variation of viscosity with temperature

Description : Phenols are added in gasoline to (A) Improve the octane number (B) Act as an antioxidant (C) Reduce its viscosity (D) Increase its pour point

Last Answer : (B) Act as an antioxidant

Description : Tetra-ethyl lead is added in gasoline to (A) Increase its smoke point (B) Reduce gum formation (C) Reduce the pour point (D) Increase its octane numbe

Last Answer : (D) Increase its octane numbe

Description : The average boiling point of aviation turbine fuel is closest to that of (A) Lubricating oils (B) LPG (C) Diesel (D) Kerosene

Last Answer : (D) Kerosene

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 : The temperature at which fuel flows to case is called.... (a) Fire point (b) Flash point (c) Pour point (d) Cloud point

Last Answer : c) Pour point

Description : iesel engine has less reserve torque then spark ignition because ∙ Torque-speed curve is governed by volumetric efficiency of fuel pump and engine cylinder ∙ Torque is a function of thermal efficiency ∙ Diesel engine has generally low speed engine ∙ None of the above

Last Answer : ∙ Torque is a function of thermal efficiency

Description : Which of the following statement is incorrect?  A. The liquid fuels consist of hydrocarbons.  B. The liquid fuels have higher calorific value than solid fuels.  C. The solid fuels have higher calorific value than liquid fuels.  D. A good fuel should have low ignition point.

Last Answer : Answer: C

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

Description : Which of the following is the most important property for a jet fuel? (A) Cloud point (B) Pour point (C) Colour (D) Freezing point

Last Answer : (D) Freezing point

Description : A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel ... an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.

Last Answer : ANSWER c. The compression ratio of a diesel engine is higher than that of an S.I engine

Description : Refractive index of a petrofuel which is the ratio of velocity of light in air to its velocity in the petrofuel gives an indication if its (A) Molecular weight (B) Aromatics content (C) Both ‘a’ & ‘b’ (D) Neither ‘a’ nor ‘b’

Last Answer : (C) Both ‘a’ & ‘b

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 : Pick out the wrong statement. (A) Aromatics have higher specific gravity than paraffins (B) Gross calorific value (GCV) of petrofuels is equal to (12400 - 2100 ρ 2 ) where, ρ is the specific gravity ... volume basis (i.e., Kcal/litre) (D) Higher specific gravity of petrofuels means higher C/H ratio

Last Answer : (C) Heavier petrofuels have higher GCV on weight basis (i.e., Kcal/kg) but lower GCV on volume basis (i.e., Kcal/litre)

Description : Phosphorus is kept in water because – (1) its ignition temperature is very high (2) its ignition temperature is very low (3) its critical temperature is high (4) its critical temperature is low

Last Answer : (2) its ignition temperature is very low Explanation: The allotropic form of Phosphorus (white phosphorus) is less stable and therefore highly reactive because of angular strain in P4 molecule where the angles are only 600.

Description : Phosphorus is kept in water because (1) its ignition temperature is very high (2) its ignition temperature is very low (3) its critical temperature is high (4) its critical temperature is low

Last Answer : its ignition temperature is very low

Description : Asphalts are (A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Last Answer : (C) Readily oxidisable and form carbonaceous sludge

Description : Performance number of a liquid fuel is related to its (A) Wax content (B) Spontaneous ignition temperature (C) Knocking tendency (D) Sulphur content

Last Answer : (B) Spontaneous ignition temperature

Description : Ignition temperature of a fuel in air is __________ that in pure oxygen. (A) More than (B) Less than (C) Equal to (D) Either more or less; depends on the type of fuel

Last Answer : (A) More than