240 Important Internal Combustion Engines MCQ Question and Answer | PDF Free Download
1.The scavenging efficiency of a four stroke cycle diesel engine is
- ABelow 50%
- BBetween 50 and 85%
- CBetween 85 and 95%
- DBetween 95 and 100%
2.Scavenging is usually done to increase
- AThermal efficiency
- BSpeed
- CPower output
- DFuel consumption
3.Which of the following medium is compressed in a Diesel engine cylinder?
- AAir alone
- BAir and fuel
- CAir and lub oil
- DFuel alone
4.Number of working strokes per min. for a four stroke cycle engine are _________ the speed of the engine in r.p.m.
- AEqual to
- BOne-half
- CTwice
- DFour-times
5.Number of working strokes per min. for a two stroke cycle engine are _________ the speed of the engine in r.p.m.
- AEqual to
- BOne-half
- CTwice
- DFour-times
6.The pressure at the end of compression, in diesel engines, is approximately
- A10 bar
- B20 bar
- C25 bar
- D35 bar
7.The pressure at the end of compression, in petrol engines, is approximately
- A10 bar
- B20 bar
- C25 bar
- D35 bar
8.Air fuel ratio for idling speed of a petrol engine is approximately
- A1 : 1
- B5 : 1
- C10 : 1
- D15 : 1
9.The specific fuel consumption per BH hour for a petrol engine is approximately
- A0.15 kg
- B0.2 kg
- C0.25 kg
- D0.3 kg
10.Engine pistons are usually made of aluminium alloy because it
- AIs lighter
- BWear is less
- CAbsorbs shocks
- DIs stronger
11.The reason for supercharging in any engine is to
- AIncrease efficiency
- BIncrease power
- CReduce weight and bulk for a given output
- DEffect fuel economy
12.Morse test can be conducted for
- APetrol engines
- BDiesel engines
- CMulti cylinder engines
- DAll of these
13.The cetane (C₁₆H₃₄) which is a straight chain paraffin, is assigned a cetane number of
- A0
- B50
- C100
- D150
14.Alpha-methyl-naphthalene (C₁₁ H₁₀) has a cetane number of
- A0
- B50
- C100
- D150
15.The specific fuel consumption per BHP hour for diesel engine is approximately
- A0.15 kg
- B0.2 kg
- C0.25 kg
- D0.3 kg
16.The maximum propulsive efficiency of a turbojet engine is at a speed of
- A1000 km/h
- B2000 km/h
- C2400 km/h
- D3000 km/h
17.The method of determination of indicated power of a multi cylinder spark ignition engine is by the use of
- AMorse test
- BProny brake test
- CMotoring test
- DHeat balance test
18.The air-fuel ratio of the petrol engine is controlled by
- AFuel pump
- BGovernor
- CInjector
- DCarburettor
19.The air-fuel ratio in petrol engines is controlled by
- AControlling valve opening/closing
- BGoverning
- CInjection
- DCarburetion
20.A spark plug gap is kept from
- A0.3 to 0.7 mm
- B0.2 to 0.8 mm
- C0.4 to 0.9 mm
- D0.6 to 1.0 mm