240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.If petrol is used in a diesel engine, then
- ALow power will be produced
- BEfficiency will be low
- CHigher knocking will occur
- DBlack smoke will be produced
2.The calorific value of gaseous fuels is expressed in terms of
- AKcal
- Bkcal/kg
- Ckcal/m²
- Dkcal/m3
3.A diesel engine has compression ratio from
- A6 to 10
- B10 to 15
- C15 to 25
- D25 to 40
4.A petrol engine has compression ratio from
- A6 to 10
- B10 to 15
- C15 to 25
- D25 to 40
5.In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the
- ABeginning of suction stroke
- BEnd of suction stroke
- CBeginning of exhaust stroke
- DEnd of exhaust stroke
6.A diesel engine has
- A1 valve
- B2 valves
- C3 valves
- D4 valves
7.The pressure inside the cylinder is _________ the atmospheric pressure during the exhaust stroke.
- AEqual to
- BBelow
- CAbove
- DNone of these
8.Pick up the false statement
- AThermal efficiency of diesel engine is about 34%
- BTheoretically correct mixture of air and petrol is approximately 15:1
- CHigh speed compression engines operate on dual combustion cycle
- DS.I. engines are quality governed engines
9.The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is
- ASame
- BMore
- CLess
- DLess or more depending on operating conditions
10.The air requirement of a petrol engine during starting compared to theoretical air required for complete combustion is
- AMore
- BLess
- CSame
- DMay be more or less depending on engine capacity
11.Which of the following fuel detonates readily
- ABenzene
- BIso-octane
- CNormal heptanes
- DAlcohol
12.Pour point of fuel oil is the
- AMinimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
- BTemperature at which it solidifies or congeals
- CIt catches fire without external aid
- DIndicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off
13.The function of a distributor in a coil ignition system of I.C. engines is
- ATo distribute spark
- BTo distribute power
- CTo distribute current
- DTo time the spark
14.Compression ratio of I.C. Engines is
- AThe ratio of volumes of air in cylinder before compression stroke and after compression stroke
- BVolume displaced by piston per stroke and clearance volume in cylinder
- CRatio of pressure after compression and before compression
- DSwept volume/cylinder volume
15.The pressure and temperature at the end of compression stroke in a petrol engine are of the order of
- A4-6 kg/cm² and 200-250°C
- B6-12 kg/cm² and 250-350°C
- C12-20 kg/cm² and 350-450°C
- D20-30 kg/cm² and 450-500°C
16.The brake power is the power available
- AIn the engine cylinder
- BAt the crank shaft
- CAt the crank pin
- DNone of these
17.Which one of the following engines will have heavier flywheel than the remaining ones?
- A30 kW four-stroke petrol engine running at 1500 r.p.m.
- B30 kW two-stroke petrol engine running at 1500 r.p.m.
- C30 kW two-stroke diesel engine running at 750 r.p.m.
- D30 kW four-stroke diesel engine running at 750 r.p.m.
18.In a typical medium speed 4-stroke cycle diesel engine the inlet valve
- AOpens at 20° before top dead center and closes at 35° after the bottom dead center
- BOpens at top dead center and closes at bottom dead center
- COpens at 10° after top dead center and closes 20° before the bottom dead center
- DMay open or close anywhere
19.The effective inhibitor of pre-ignition is
- AAlcohol
- BWater
- CLead
- DNone of these
20.The brake power (B.P.) of the engine is given by (where W = Brake load or dead load in newtons, l = Length of arm in meters, N = Speed of engine in r.p.m., S = Spring balance reading in newtons, D = Dia. of brake drum in meters, and d = Dia. of rope in meters)
- AB.P = (Wl × 2πN)/60 watts
- BB.P = [(W - S) πDN]/60 watts
- CB.P = [(W - S) π (D + d) N]/60 watts
- DAll of these