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 : A fuel of cetane number 40 has the same ignition quality as a mixture of a) 40% cetane and 60% alpha methyl naphthalene b) 40% alpha methyl naphthalene and 60% cetane c) 40% petrol and 60% diesel d) 40% diesel and 60% petrol
Last Answer : Answer: a Explanation: A fuel of cetane number 40 has the same ignition quality as a mixture of 40% cetane and 60% alpha methyl naphthalene as cetane number is counted on cetane percentage.
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 : Visbreaking process is used mainly for making (A) High cetane diesel (B) High octane gasoline (C) Fuel oil (D) Smoke free kerosene
Last Answer : (C) Fuel oil
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 : 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 : 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 : Ignition quality of diesel is expressed by a. octane number b. cetane number c. calorific value d. carbon content
Last Answer : ANSWER b. cetane 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 : By higher octane number of SI fuel, it is meant that the fuel has (a) Higher heating value (b) Higher flash point (c) Lower volatility (d) Longer ignition delay
Last Answer : Ans : d
Description : The tendency of a diesel engine to knock increases if a. engine speed is increased b. engine power is increased c. cetane number of the fuel is increased d. compression ratio is increased
Last Answer : ANSWER d. compression ratio is increased
Description : The knock in diesel engine occurs due to A. instantaneous and rapid burning of the first part of the charge B. instantaneous auto ignition of the last part of the charge C. delayed burning of the last part of the charge D. reduction of delay period
Last Answer : ANSWER : A
Description : Write the values of boiling temperature for cetane(diesel).iso-octane(petrol), Butane, Propane an methane fuel and write effect of it on its system.
Last Answer : Write the values of boiling temperature for cetane(diesel).iso-octane(petrol), Butane, Propane an methane fuel and write effect of it on its system.
Description : Dearomatization of kerosene (by liquid sulphur dioxide extraction) is done to (A) Increase its smoke point (B) Improve its oxidation stability (C) Decrease the breathing loss (D) None of these
Last Answer : (B) Improve its oxidation stability
Description : Diesel index (an alternative index for expressing the quality of diesel) is (A) Determined by using a test engine (B) Not related to aniline point (C) Equal to cetane number plus 3 (D) All (A), (B) & (C)
Last Answer : (C) Equal to cetane number plus 3
Description : gnition delay is defined as the A)time between start of fuel injection and ignition of fuel B)time between end of fuel injection and ignition of fuel C)time between start of ignition and tdc D)time between completion of ignition and bdc
Last Answer : A)time between start of fuel injection and ignition of fuel
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
Description : Ignition quality of petrol is expressed by a. Octane number b. cetane number c. calorific value d. self-ignition temperature
Last Answer : ANSWER a. Octane number
Description : Cetane number of diesel used in trucks may be about (A) 50 (B) 14 (C) 35 (D) 85
Last Answer : (A) 50
Description : Which of the following additives improves the cetane number of diesel? (A) Amyl nitrate (B) Ethyl mercaptan (C) Naphthenic acid (D) Tetra ethyl lead
Last Answer : (B) Ethyl mercaptan
Description : Cetane number of high speed diesel must be ≥ (A) 30 (B) 45 (C) 75 (D) 95
Last Answer : (B) 45
Description : Diesel used in naval applications has a minimum cetane number of (A) 25 (B) 35 (C) 45 (D) 65
Last Answer : (C) 45
Description : Which of the following is an additive used for improving the cetane number of diesel? (A) Tetraethyl lead (B) Tetramethyllead (C) Ethyl nitrate or acetone (D) None of these
Last Answer : (A) Tetraethyl lead
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 : 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 : Compare detonation and diesel knock on the basis of (i) Fuel Ignition Temperature (ii) Compression Ratio (iii) Speed (iv) inlet temperature (v) inlet pressure (vi) cylinder wall temperature (vii) cylinder size
Last Answer : Comparison between detonation and diesel knock: Parameter To avoid Detonation in SI Engine To avoid Diesel knock i) Fuel Ignition Temperature High Low ii) Compression Ratio ... Cylinder wall temperature Low High viii) Cylinder size Small Large
Description : For the best results of efficient combustion, high speed diesel engines need an approximate cetane number of a. 100 b. 50 c. 10 d. 5
Last Answer : ANSWER b. 50
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 : Which of the following has the highest viscosity of all (at a given temperature)? (A) Naphtha (B) Fuel oil (C) Light diesel oil (D) Petrol
Last Answer : (B) Fuel oil
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 : The two reference fuel used for cetane rating are (a) Cetane and iso octane (b) Cetane and tetra ethyl lead (c) Cetance and n-heptane (d) Cetane and α- methyl naphthalene
Description : Spark plug is provided in a/an (A) Engine having carburettor (B) Diesel engine (C) Compression ignition engine (D) Both (B) & (C)
Last Answer : (A) Engine having carburettor
Description : Which of the following is not applicable to liquid fuels? a) the viscosity of a liquid fuel is a measure of its internal resistance to flow. b) the viscosity of all liquid fuels decreases with ... the viscosity of liquid fuels, higher will be its heating value d) viscous fuels need heat tracing
Last Answer : c) higher the viscosity of liquid fuels, higher will be its heating value
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 : 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 : 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 : 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 : What causes ignition to occur in a diesel engine?
Last Answer : When the piston compresses the fuel-air mixture, the spark ignites it, causing combustion
Description : Most high speed compression ignition engine operate on A. dual cycle B. otto cycle C. diesel cycle D.Carnot cycle
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 : The self-ignition temperature of diesel as compared to petrol is a. higher b. lower c. same d. varies
Description : Which of the following cycle is used for Compression Ignition engine? a. Otto cycle b. Diesel cycle c. Dual cycle d. Carnot cycle
Last Answer : Answer b. Diesel cycle
Description : Which of the following cycle is used for Spark Ignition engine? a. Otto cycle b. Diesel cycle c. Dual cycle d. Carnot cycle
Last Answer : Answer a. Otto cycle
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
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 : 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 : The most important property for a jet fuel is its (A) Viscosity (B) Freezing point (C) Calorific value (D) Flash poin
Last Answer : (B) Freezing point
Description : Neoprene which is used for making shoe heels & belts is superior to natural rubber in its stability to aerial oxidation and resistance to oils & other solvents. The monomer used for making neoprene is (A) Chloroethane (B) Chloroprene (C) Isoprene (D) None of these
Last Answer : (B) Chloroprene
Description : Stabilisation of gasoline (petrol) means (A) Removal of dissolved gases from it (B) Increasing its oxidation stability (C) Improving its lead susceptibility (D) Increasing its vapour pressure
Last Answer : (A) Removal of dissolved gases from it