240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.The ignition quality of diesel oil is expressed by
- ACetane number
- BOctane number
- CCalorific value
- DNone of these
2.The ignition quality of petrol is expressed by
- ACetane number
- BOctane number
- CCalorific value
- DAll of these
3.The specific fuel consumption per B.P. hour for a diesel engine is about
- A0.2 kg
- B0.25 kg
- C0.3 kg
- D0.35 kg
4.The power actually developed by the engine cylinder of an I.C. engine is known as
- ATheoretical power
- BActual power
- CIndicated power
- DNone of these
5.The loud pulsating noise heard within the cylinder of an internal combustion engine is known as
- ADetonation
- BTurbulence
- CPre-ignition
- DSupercharging
6.The mechanical efficiency (ηm) of the engine is given by
- Aηm = B.P/I.P
- Bηm = I.P/B.P
- Cηm = (B.P × I.P)/100
- DNone of these
7.A diesel engine is _________ as compared to petrol engine, both running at rated load.
- AEqually efficient
- BLess efficient
- CMore efficient
- DNone of these
8.The ratio of the work obtained at the crankshaft in a given time to the energy supplied during the same time is called
- AMechanical efficiency
- BOverall efficiency
- CIndicated thermal efficiency
- DVolumetric efficiency
9.The cetane number of diesel oil, generally available, is
- A20 to 25
- B25 to 30
- C30 to 40
- D40 to 55
10.The octane number of petrol, generally available, is
- A20 to 40
- B40 to 60
- C60 to 80
- D80 to 100
11.In a typical medium speed 4-stroke cycle diesel engines
- AExhaust valve opens at 35° before bottom dead center and closes at 20° after top dead center
- BExhaust valve opens at bottom dead center and closes at top dead center
- CExhaust valve opens just after bottom dead center and closes just before top dead center
- DMay open and close anywhere
12.Antiknock for compression ignition engines is
- ANapthene
- BTetra ethyl lead
- CAmyl nitrate
- DAmyl nitrate
13.The combustion in compression ignition engines is
- AHomogeneous
- BHeterogeneous
- CBoth (A) and (B)
- DLaminar
14.High speed compression engines operate on
- AOtto cycle
- BDiesel cycle
- CDual combustion cycle
- DAll of these
15.Most high speed compression engines operate on
- ADiesel cycle
- BOtto cycle
- CDual combustion cycle
- DSpecial type of air cycle
16.The correct mixture strength (by weight) for petrol is about
- A14.6 : 1
- B18.5 : 1
- C20.4 : 1
- D22.6 : 1
17.The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is
- ASame
- BLess
- CMore
- DMore or less depending on power rating
18.The process of breaking up or a liquid into fine droplets by spraying is called
- AVaporisation
- BCarburetion
- CIonization
- DAtomization
19.The correct sequence of the decreasing order of brake thermal efficiency of the three given basic types of engines is
- AFour stroke C.I. engine, four stroke S.I. engine, two stroke S.I. engine
- BFour stroke S.I. engine, four stroke C.I. engine, two stroke S.I. engine
- CFour stroke C.I. engine, two stroke S.I. engine, four stroke S.I. engine
- DTwo stroke S.I. engine, four stroke S.I. engine, four stroke C.I. engine
20.The compensating jet in a carburettor supplies almost constant amount of petrol at all speeds because the
- AJet area is automatically varied depending on the suction
- BThe flow from the main jet is diverted to the compensating jet with increase in speed
- CThe diameter of the jet is constant and the discharge coefficient is invariant
- DFlow is produced due to the static head in the float chamber