240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.The ignition of the charge by some hot surface within the engine before the passage of spark is called
- APre-ignition
- BDetonation
- CIgnition delay
- DAuto-ignition
2.The air standard efficiency of an I.C. engine is given by (where r = Compression ratio, and γ = Ratio of specific heats)
- A1 - rγ - 1
- B1 + rγ – 1
- C1 - (1/rγ - 1)
- DNone of these
3.The frictional power (F.P.) is given by
- AF.P. = B.P. - I.P.
- BF.P. = I.P. - B.P.
- CF.P. = B.P./I.P.
- DF.P. = I.P./B.P.
4.The operation of forcing additional air under pressure in the engine cylinder is known as
- AScavenging
- BTurbulence
- CSupercharging
- DPre-ignition
5.The knock in diesel engine occurs due to
- AInstantaneous and rapid burning of the first part of the charge
- BInstantaneous auto ignition of last part of charge
- CDelayed burning of the first part of the charge
- DReduction of delay period
6.An engine indicator is used to determine the following
- ASpeed
- BTemperature
- CVolume of cylinder
- Dm.e.p. and I.H.P.
7.Morse test is used to determine the I.P. of a
- ASingle cylinder petrol engine
- BFour stroke engine
- CSingle cylinder diesel engine
- DMulti cylinder engine
8.The delay period in compression ignition engines depends upon
- ATemperature and pressure in the cylinder at the time of injection
- BNature of the fuel mixture strength
- CRelative velocity between the fuel injection and air turbulence pressure of residual gases
- DAll of the above
9.If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be
- A2%
- B4%
- C8%
- D14%
10.Supercharging is essential in
- ADiesel engines
- BGas turbines
- CPetrol engines
- DAircraft engines
11.The colour of exhaust from diesel engine is generally
- AWhite
- BBluish
- CBlack
- DViolet
12.The firing order in an I.C. engine depends upon
- AArrangement of the cylinders
- BDesign of crankshaft
- CNumber of cylinders
- DAll of these
13.A diesel engine, during suction stroke, draws
- AAir only
- BDiesel only
- CA mixture of diesel and air
- DNone of these
14.A petrol engine, during suction stroke draws
- AAir only
- BPetrol only
- CA mixture of petrol and air
- DNone of these
15.The object of providing masked inlet valve in the air passage of compression ignition engines is to
- AEnhance flow rate
- BControl air flow
- CInduce primary swirl
- DInduce secondary turbulence
16.Stoichiometric ratio is
- AChemically correct air-fuel ratio by weight
- BChemically correct air-fuel ratio by volume
- CActual air-fuel ratio for maximum efficiency
- DNone of the above
17.The thermal efficiency of a standard Otto cycle for a compression ratio of 5.5 will be
- A25%
- B50%
- C70%
- D100%
18.The object of supercharging the engine is
- ATo reduce mass of the engine per brake power
- BTo reduce space occupied by the engine
- CTo increase the power output of an engine when greater power is required
- DAll of the above
19.The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called
- ANet efficiency
- BEfficiency ratio
- CRelative efficiency
- DOverall efficiency
20.If the speed of the engine is increased, the indicated power will
- AIncrease
- BDecrease
- CRemain same
- DNone of these