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
Last Answer : Ans : d
Description : Reference fuels for knock rating of SI engine fuels would include (a) Iso octane alpha methyl naphthalene (b) Normal octance and aniline (c) Isooctance and n octane (d) N heptane and iso octane
Description : Octane number of gasoline is obtained by comparing the performance of the engine when running on a mixture of the following hydrocarbons A. ethane and methane B. normal heptane and iso-octane C. iso-heptane and octane D. iso-octane and TEL
Last Answer : ANSWER : B
Description : A mixture containing 65% of iso-octane and 35% of normal heptane will have a) cetane number 65 b) octane number 65 c) cetane number 35 d) octane number 35
Last Answer : Answer: b Explanation: A mixture containing 65% of iso-octane and 35% of normal heptane will have octane number 65 as octane number is the number percentage containing iso-octane.
Description : Which of the following fuel detonates readily? a) Benzene b) Iso-octane c) Normal heptane d) Alcohol
Last Answer : Answer: c Explanation: Normal heptane detonates readily.
Description : Which of the following fuel has little tendency towards detonation? a) Benzene b) Iso-octane c) Normal heptane d) Alcohol
Last Answer : Answer: b Explanation: Benzene has little tendency towards detonation.
Description : The normal heptane(C7H16) is given a rating of ____________ octane number. a) 0 b) 50 c) 100 d) 120
Last Answer : Answer: a Explanation: None.
Description : Gasoline with an octane number of 90 is equivalent in knocking characteristics to a mixture of heptane and isooctane of the following composition : (a) 20% heptane + 80% isooctane (b) 90% heptane + 10% isooctane (c) 80% heptane + 20% isooctane (d) 10% heptane + 90% isooctane
Last Answer : 10% heptane + 90% isooctane
Description : If petrol is used in a diesel engine a. higher knocking will occur b. efficiency will be low c. low power will be obtained d. black smoke will be produced
Last Answer : ANSWER a. higher knocking will occur
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 : 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 : What is the quality rating for diesel fuel, similar to the octane number for petrol?
Last Answer : Catane number
Description : Use of gasoline blend like tetraethyl lead in internal combustion engine a. increases the octane rating of the fuel b. allows engine to operate at higher compression ratio c. avoids auto-ignition of fuel d. all of the above
Last Answer : ANSWER d. all of the above
Description : A fuel with octane number 90 means it is as good as a mixture of : (a) 90% Isooctane + 10% n-heptane (b) 90% n-Heptane + 10% isooctane (c) 2 Litre of 90% isooctane + 2 litre of benzene (d) 2 Litre of 90% n-heptane + 2 litre of benzene
Last Answer : 90% Isooctane + 10% n-heptane
Description : In any fuel, the percentage by volume of isooctane in a mixture of isooctane and n-heptane which will knock under same conditions as the fuel being tested, is called : (a) Cracking (b) Iodine number (c) Aromatization (d) Octane number
Last Answer : Octane number
Description : The compound that has the least value for octane number is – (1) 2-methyl heptane (2) Iso-octane (3) 2,2-dimethyl hexane (4) n-heptane
Last Answer : (4) n-heptane Explanation: Octane rating or octane number is a standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand. Isooctane (upper) has an octane rating of 100 whereas n-heptane has an octane rating of O.
Description : The compound that has the least value for octane number is : (1) 2-methyl heptane (2) Iso-octane (3) 2,2-dimethyl hexane (4) n-heptane
Last Answer : n-heptane
Description : If the performance of diesel engine of different sizes, cylinder dimensions and power rating are to be compared, which of the following parameters can be used for such comparison? (a) Swept volume (b) Air fuel ratio (c) Specific brake fuel consumption (d) Volumetric efficiency
Last Answer : Ans :c
Description : The specific fuel consumption of a petrol engine compared to diesel engine of same H.P is A. same B.more C. less D. unpredictable
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 : 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 : 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 : Octane number of petrol normally used in petrol engines is of the order of a. 20-30 b. 40-60 c. 60-70 d. 80-90
Last Answer : ANSWER d. 80-90
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 : Accumulators should have adequate volume to store refrigerant charge at least (a) 10% (b) 25% (c) 50% (d) 75%
Last Answer : Ans: c
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 : 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
Description : The compression ratio cannot be increased beyond certain limit as it results in a. auto-ignition of fuel b. detonation c. engine knocking d. all the above
Last Answer : ANSWER d. all the above
Description : The theoretical minimum work required to separate one mole of a liquid mixture at 1 atm, containing 50 mole % each of n- heptane and n octane into pure compounds each at 1 atm is (A) -2 RT ln 0.5 (B) -RT ln 0.5 (C) 0.5 RT (D) 2 RT
Last Answer : (B) -RT ln 0.5
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
Description : The thermal efficiency of a diesel engine is of the order of a. 92% b. 68% c. 34% d. 25%
Last Answer : ANSWER c. 34%
Description : Supercharging is essential in A. aircraft engines B. petrol engines C. gas turbines D. diesel engines
Last Answer : ANSWER : A
Description : A diesel engine compared to petrol engine, running at full load is A. less efficient B. equally efficient C. more efficient D. other factors will decide it
Last Answer : ANSWER : C
Description : Diesel as compared to petrol is a. more difficult to ignite b. less difficult to ignite c. highly ignitable d. just about the same difficult to ignite
Last Answer : ANSWER a. more difficult to ignite
Description : If diesel is used in a petrol engine a. engine will not run b. engine detonates c. engine gives smoke d. engine knocks
Last Answer : ANSWER a. engine will not run
Description : For low load operation more economical engine is a. petrol engine b. diesel engine c. muticylinder engine d. two stroke engine
Last Answer : ANSWER b. diesel engine
Description : Which of the following is not an internal combustion engine? a. petrol engine b. steam turbine c. diesel engine d. gas turbine
Last Answer : ANSWER b. steam turbine
Description : A spark plug is used in a. petrol engine b. diesel engine c. gas engine d. steam engine
Last Answer : ANSWER a. petrol engine
Description : The self-ignition temperature of diesel as compared to petrol is a. higher b. lower c. same d. varies
Description : Which hydrocarbon molecule with eight carbons would produce the lowest octane number (i.e., the most knocking) when used as a fuel in automobile? (a) 2-Methyl-3,3-dimethylpentane (b) n-Octane (c) 2-Isopropylpentane (d) 2-Methylheptane
Last Answer : n-Octane
Description : Tetraethyl lead (TEL) is added to petrol to (a) prevent its freezing (b) increase its boiling point (c) increase its flash point (d) increase its anti-knocking rating
Last Answer : Ans:(d)
Description : The specific gravity of petrol is about a. 0.65 b. 0.75 c. 0.85 d. 0.95
Last Answer : ANSWER b. 0.75
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 : Air fuel ratio at which a petrol engine cannot work is A. 8:1 B. 12:1 C. 15:1 D. 20:1 and less
Last Answer : ANSWER : D
Description : Air fuel ratio for idling speed of a petrol engine is approximately A. 1:1 B. 5:1 C. 20:1 D. 10:1
Description : The theoretically correct air fuel ratio of a petrol engine is of the order of A. 6:1 B. 10:1 C. 15:1 D. 20:1
Description : The fuel air ratio in a petrol engine fitted with suction carburetor, operating with dirty air filter as compared to clean filter will be A. higher B. lower C. remain unaffected D. unpredictable
Description : The air-fuel ratio of the petrol engine is governed by A. fuel pump B. governor C. carburetor D. injector
Description : The stoichiometric air fuel ration for petrol is 15:1 . What is the air fuel ratio required for maximum power? (a) 16:1 – 18:1 (b) 15:1 (c) 12:1 – 14:1 (d) 9:1 – 11:1
Description : Air fuel ratio at which a petrol engine cannot work is a. 8:1 b. 10:1 c. 20:1 and less d. 15:1
Last Answer : ANSWER c. 20:1 and less