240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.The temperature of interior surface of cylinder wall in normal operation is not allowed to exceed
- A80°C
- B120°C
- C180°C
- D240°C
2.A stoichiometric air-fuel ratio is
- AChemically correct mixture
- BLean mixture
- CRich mixture for idling
- DRich mixture for over loads
3.An hmh flame speed is obtained in diesel engine when air fuel ratio is
- AUniform throughout the mixture
- BChemically correct mixture
- CAbout 35% of rich mixture
- DAbout 10% of rich mixture
4.In a four stroke cycle petrol engine, the compression
- AStarts at 40° after bottom dead centre and ends at 30° before top dead centre
- BStarts at 40° before bottom dead centre and ends at 30° after bottom dead centre
- CStarts at bottom dead centre and ends at top dead centre
- DMay start and end anywhere
5.In a four stroke cycle diesel engine, the compression
- AStarts at 40° after bottom dead center and ends at 10° before top dead center
- BStarts at 40° before top dead center and ends at 40° after top dead center
- CStarts at top dead center and ends at 40° before bottom dead center
- DMay start and end anywhere
6.In compression ignition engines, swirl denotes a
- AHaphazard motion of the gases in the chamber
- BRotary motion of the gases in the chamber
- CRadial motion of the gases in the chamber
- DNone of the above
7.The thermal efficiency of diesel engines on weak mixtures is
- AUnaffected
- BLower
- CHigher
- DDependent on other factors
8.Fuel oil consumption guarantees for I .C. engine are usually based on
- ALow heat value of oil
- BHigh heat value of oil
- CNet calorific value of oil
- DCalorific value of fuel
9.Fuel consumption of diesel engines is not guaranteed at one quarter load because at such low loads
- AThe friction is high
- BThe friction is unpredictable
- CThe small difference in cooling water temperature or in internal friction has a disproportionate effect
- DThe engine is rarely operated
10.Diesel fuel as compared to petrol fuel is
- AHighly ignitable
- BMore difficult to ignite
- CLess difficult to ignite
- DNone of these
11.A 75 cc engine has following parameter as 75 cc
- AFuel tank capacity
- BLube oil capacity
- CSwept volume
- DCylinder volume
12.Diesel engine can work on very lean air fuel ratio of the order of 30: 1. A petrol engine can also work on such a lean ratio provided
- AIt is properly designed
- BBest quality fuel is used
- CCannot work as it is impossible
- DFlywheel size is proper
13.In order to mix air and petrol in the required proportion and to supply it to the engine during suction stroke, then _________ is employed
- AFuel pump
- BInjector
- CCarburettor
- DNone of these
14.The normal heptane (C₇H₁₆) is given a rating of ________ octane number.
- A0
- B50
- C100
- D150
15.In order to eliminate knocking in compression ignition engines, there should be
- AShort delay period
- BLate auto-ignition
- CLow compression ratio
- DHigh self ignition temperature of fuel
16.In a four stroke cycle petrol engine, the inlet valve
- AOpens at top dead center and closes at bottom dead center
- BOpens at 20° before top dead center and closes at 40° after bottom dead center
- COpens at 20° after top dead center and closes at 20° before bottom dead center
- DMay open or close anywhere
17.In a four stroke cycle diesel engine, the inlet valve
- AOpens at 20° before top dead center and closes at 40° after bottom dead center
- BOpens at 20° after top dead center and closes at 20° before bottom dead center
- COpens at top dead center and closes at bottom dead center
- DMay open and close anywhere
18.The knocking in spark ignition engines can be reduced by
- ARetarding the spark
- BIncreasing the engine speed
- CBoth (A) and (B)
- DNone of these
19.The purpose of testing an internal combustion engine is
- ATo determine the information, which cannot be obtained by calculations
- BTo conform the data used in design, the validity of which may be doubtful
- CTo satisfy the customer regarding the performance of the engine
- DAll of the above
20.The magneto in an automobile is basically
- ATransformer
- BD.C. generator
- CCapacitor
- DCapacitor