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 : Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
Last Answer : ANSWER d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
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 : 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 : Most high-speed compression engines operate on a. diesel cycle b. Otto cycle c. dual cycle d. Carnot cycle
Last Answer : ANSWER c. dual cycle
Description : As a result of detonation in Internal combustion engines the following parameter attains very high value. a. peak pressure b. rate of rise of pressure c. rate of rise of temperature. d. peak temperature.
Last Answer : ANSWER b. rate of rise of pressure
Description : With EFI of diesel engines a) sharp start and stop is not possible b) very high injection pressure can be obtained c) sudden cylinder cut-off is impossible d) diagnostic properties are poor
Last Answer : Answer: b Explanation: Generally, with EFI of diesel engines very high injection pressure can be obtained.
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 : Supercharging is essential in A. aircraft engines B. petrol engines C. gas turbines D. diesel engines
Last Answer : ANSWER : A
Description : For the same capacity engines, the compression ratio of diesel engine a. is lower than the compression ratio of SI engine b. is higher than the compression ratio of SI engine c. is same as the compression ratio of SI engine d. cannot say
Last Answer : ANSWER b. is higher than the compression ratio of SI engine
Description : Cetane number of petrol is around a. 10 b. 15-20 c. 35 d. 55-70
Last Answer : ANSWER b. 15-20
Description : In a 4 S diesel engine, the term ‘squish’ refers to the (a) Injection of fuel in the precombustion chamber (b) Discharge of gases from the precombustion chamber (c) Entry of air into the combustion chamber (d) Stripping of fuel from the core
Last Answer : Ans :c
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 : In diesel engine, the fuel is ignited by a. spark b. injected fuel c. heat resulting from compressing air that is supplied for combustion d. ignitor
Last Answer : ANSWER c. heat resulting from compressing air that is supplied for combustion
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 : 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 : 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 : 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 : 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 : 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 : For the same peak pressure and heat input a. Otto cycle is more efficient b. Diesel cycle is more efficient c. Both are equally efficient d. None of the above
Last Answer : ANSWER b. Diesel cycle is more efficient
Description : For same compression ratio and heat input a. Otto cycle is more efficient b. Diesel cycle is more efficient c. Both are equally efficient d. None of the above
Last Answer : ANSWER a. Otto cycle is more efficient
Description : A 40 kW engine has a mechanical efficiency of 80 %. If the frictional power is assumed to be constant with load, what is the approximate value of the mechanical efficiency at 50 % of the rated load? (a) 45% (b) 55 % (c) 65% (d) 75%
Description : Cetane number of high speed diesel must be ≥ (A) 30 (B) 45 (C) 75 (D) 95
Last Answer : (B) 45
Description : Which of the following factors increases the tendency of knocking in the CI engines? (a) Increasing both the r and coolant temperatures (b) Increasing both the speed and the injection advance (c) Increasing the speed, injection advance and coolant temperature (d) Increasing the compression ratio
Description : The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b d. None of these.
Last Answer : ANSWER c. Both a and b.
Description : The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b. d. None of these.
Last Answer : ANSWER c. Both a and b
Description : Most high speed compression ignition engine operate on A. dual cycle B. otto cycle C. diesel cycle D.Carnot cycle
Description : Cetane number of diesel used in trucks may be about (A) 50 (B) 14 (C) 35 (D) 85
Last Answer : (A) 50
Description : Alcohols alone cannot be used in CI engines as a) their self ignition temperature is high b) latent heat of vaporization is high c) all of the mentioned d) none of the mentioned
Last Answer : Answer: c Explanation: None.
Description : The output of a diesel engine can be increased without increasing the engine speed or size in the following way A. feeding more fuel B. increasing the flywheel size C. heating intake air D. supercharging
Last Answer : ANSWER : D
Description : In a typical medium speed 4- stroke Diesel engine, the inlet valve A. opens 20°before top dead centre and closes at 35°afterthebottomdead centre. B. opens up at top dead centre and closes at bottomdead centre C. may open orcloseanywhere D. remains open for 200°
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 : Which of the following best describes both Stirling and Ericson engines? a. Internal combustion engine b. External combustion engine c. Diesel cycle d. Rankine cycle
Last Answer : External combustion engine
Description : The general rule for rating refrigeration systems (excepting for CO2 system) is to approximate following h.p. per ton of Refrigeration (a) 0.1 to 0.5 h.p. per ton of refrigeration (b) 0.5 to 0.8 h.p. per ... (c) 1 to 2 h.p. per ton of refrigeration (d) 2 to 5 h.p. per ton of refrigeration
Last Answer : Ans: c
Description : The fuel in diesel engine is normally injected at pressure of a. 5-10 kg/cm2 b. 20-25 kg/cm2 c 60-80 kg/cm2 d. 90-130 kg/cm2
Last Answer : ANSWER d. 90-130 kg/cm2
Description : In a boiler enthalpy of water supplied was 2000 kJ/kg. Enthalpy being added by fuel combustion is 3200 kJ/kg. Using first law of thermodynamics, find amount of heat supplied if steam generation rate is 10 tons per hour.
Last Answer : Heat supplied Q = m (h2-h1) …….(Steady flow energy equation for boiler) ; h2=3200 KJ/kg h1=2000 KJ/kg m = 10 Tons /hour = (10 x 1000)/3600 kg/sec = 2.77 Kg/sec Q = 2.77(3200-2000) = 3324 KJ/sec heat supplied for 10 Tons/hr steam generation
Description : Motoring test is conducted on IC engines to determine A. brake power B. indicated power C. friction power D. fuel consumption at full load
Description : Morse test is conducted on the engine to calculate the mechanical efficiency of A. single cylinder CI engine B. single cylinder SI engine C. only on two stroke engines D. multi cylinder engine
Description : In spark ignition engines, the knocking tendency can be decreased by a) decreasing compression ratio b) controlling intake throttle c) controlling ignition timing d) adding dopes like tetraethyl lead and ethylene dibromide
Last Answer : Answer: d Explanation: None.
Description : For C.I. engines fuel most preferred are a) aromatics b) paraffins c) olefins d) napthenes
Last Answer : Answer: b Explanation: For C.I. engines fuel most preferred are paraffins and for S.I. engines fuel most preferred are aromatics.
Description : For S.I. engines fuel most preferred are a) aromatics b) paraffins c) olefins d) napthenes
Last Answer : Answer: a Explanation: For S.I. engines fuel most preferred are aromatics while for C.I. engines fuel most preferred are paraffins.
Description : Which of the following statement is not correct with respect to alcohols as alternate fuel in IC engines a) anti-knock characteristics of alcohol is poor b) alcohol contains about half the heat ... /litre c) alcohol does not vaporize as easily as gasoline d) alcohols are corrosive in nature
Last Answer : Answer: a Explanation: Anti-knock characteristics of alcohol is good.
Description : Anti-knock for compression ignition engines is a) napthene b) tetra ethyl lead c) amyl nitrate d) hexadecane
Last Answer : Answer: c Explanation: Amyl nitrate is the anti-knock for compression ignition engines.
Description : The knocking tendency in CI engines increases with (a) Increase of coolant water temperature (b) Increase of temperature of inlet air (c) Decrease of compression ratio (d) Increase of compression ratio
Description : In SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature
Description : For same power output and same r, as compared to 2- stroke engines, four stroke SI engines have (a) Higher fuel consumption (b) Lower thermal efficiency (c) Highest exhaust temperatures (d) Higher thermal efficiency
Last Answer : Ans :d
Description : Which one of the following types of compressor is mostly used for supercharging of IC engines? (a) Radial flow compressor (b) Axial flow compressor (c) Root blower (d) Reciprocating compressor
Last Answer : Ans : c
Description : All heat engines utilize a. lower heating value of oil b. higher heating value of oil c. net calorific value of oil d. calorific value of fuel
Last Answer : ANSWER a. lower heating value of oil