240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.The knocking tendency in compression ignition engines for a given fuel will be
- AEnhanced by decreasing compression ratio
- BEnhanced by increasing compression ratio
- CDependent on other factors
- DNone of the above
2.The fuels in order of decreasing knock tendency for spark ignition engines are
- AParaffin, aromatic, napthene
- BParaffin, napthene, aromatic
- CNapthene, aromatics, paraffin
- DNapthene, paraffin, aromatic
3.A carburettor is used to supply
- APetrol, air and lubricating oil
- BAir and diesel
- CPetrol and lubricating oil
- DPetrol and air
4.Supercharging is the process of
- ASupplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
- BProviding forced cooling air
- CInjecting excess fuel for raising more loads
- DSupplying compressed air to remove combustion products fully
5.The reference fuels for knock rating of spark ignition engines would include
- AIso-octane and alpha-methyl naphthalene
- Bv
- CIso-octane and normal hexane
- DNormal heptane and iso-octane
6.A diesel engine as compared to petrol engine (both running and rated load) is
- AMore efficient
- BLess efficient
- CEqually efficient
- DOther factors will decide it
7.In a petrol engine, if diesel is used, then the engine will
- ANot run
- BRun more efficiently
- CRun at high speed
- DExplode
8.A supercharged engine as compared to an ordinary engine
- ARequires smaller foundation
- BIs lighter
- CConsumes less lubricating oil
- DAll of these
9.The brake power of a diesel engine, keeping other parameters constant, can be increased by
- ADecreasing the density of intake air
- BIncreasing the temperature of intake air
- CIncreasing the pressure of intake air
- DDecreasing the pressure of intake air
10.The knocking tendency in compression ignition engines for a given fuel will be
- AEnhanced by decreasing compression ratio
- BEnhanced by increasing compression ratio
- CDependent on other factors
- DNone of the above
11.The fuels in order of decreasing knock tendency for spark ignition engines are
- AParaffin, aromatic, napthene
- BParaffin, napthene, aromatic
- CNapthene, aromatics, paraffin
- DNapthene, paraffin, aromatic
12.A carburettor is used to supply
- APetrol, air and lubricating oil
- BAir and diesel
- CPetrol and lubricating oil
- DPetrol and air
13.Supercharging is the process of
- ASupplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere
- BProviding forced cooling air
- CInjecting excess fuel for raising more loads
- DSupplying compressed air to remove combustion products fully
14.The reference fuels for knock rating of spark ignition engines would include
- AIso-octane and alpha-methyl naphthalene
- BNormal octane and aniline
- CIso-octane and normal hexane
- DNormal heptane and iso-octane
15.Compression loss in I.C engines occurs due to
- ALeaking piston rings
- BUse of thick head gasket
- CClogged air inlet slots
- DAll of the above
16.The volumetric efficiency of a well designed engine may be
- A30 to 40%
- B40 to 60%
- C60 to 70%
- D75 to 90%
17.In a four stroke cycle petrol engine, the expansion
- AStarts at top dead center and ends at bottom dead center
- BStarts at 30° before top dead center and ends at 50° before bottom dead center
- CStarts at 30° after top dead center and ends at 50° after bottom dead center
- DMay start and end anywhere
18.Air fuel ratio at which a petrol engine cannot work is
- A8 : 1
- B10 : 1
- C15 : 1
- D20 : 1 and less
19.In a cycle, the spark lasts roughly for
- A1 sec
- B0.1 sec
- C0.01 sec
- D0.001 sec
20.A 5 BHP engine running at full load would consume diesel of the order of
- A0.3 kg/hr
- B1 kg/hr
- C3 kg/hr
- D5 kg/hr