IC Engines and Nuclear Power Plants for practice

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IC Engines and Nuclear Power Plants Paper Set 2

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In a four stroke cycle diesel engine, the exhaust valve

1 Opens at 30° before bottom dead centre and closes at 10° after top dead centre

2 Opens at 30° after bottom dead centre and closes at 10° before top dead centre

3 Opens at bottom dead centre and closes at top dead centre

4 May open and close anywhere

Scavenging air in diesel engine means

1 air used for combustion sent under pres-sure

2 forced air for cooling cylinder

3 burnt air containing products of combustion

4 air used for forcing burnt gases out of engine's cylinder during the exhaust period

The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

1 4 - 6 kg/cm2 and 200 - 250°

2 6 - 12 kg/cm2 and 250 - 350°C

3 12 - 20 kg/cm2 and 350 - 450°C

4 20 - 30 kg/cm2 and 450 - 500°C

5 30 - 40 kg/cm2 and 500 - 700°C

The maximum temperature in the I.C. engine cylinder is of the order of

1 500- 1000°C

2 1000- 1500°C

3 1500-2000°C

4 2000-2500°C

Combustion in compression ignition engines is

1 homogeneous

2 heterogeneous

3 both (a) and (b)

4 laminar

5 turbulent.

The specific fuel consumption per BHP hour for diesel engine is approximately

1 0.15 kg

2 0.2 kg

3 0.25 kg

4 0.3 kg

5 0.35 kg

Crankcase explosion in I.C. engines usuall occurs as

1 first a mild explosion followed by a bi explosion

2 first a big explosion followed by a mil explosion

3 both mild and big explosions occi simultaneously

4 never occurs

5 unpredictable

Compression loss in I.C engines occurs duto

1 leaking piston rings

2 use of thick head gasket

3 clogged air-inlet slots

4 increase in clearance volume caused b bearing-bushing wear

5 all of the above.

The air requirement of a petrol engine during starting compared to theoretical airequired for complete combustion is

1 more

2 loss

3 may be more or less depending on engine capacity

4 unpredictable

Pick up the false statement

1 Thermal efficiency of diesel engine i about 34%

2 Theoretically correct mixture of air am petrol is approximately 15 : 1

3 High speed compression engines operate on dual combustion cycle

4 Diesel engines are compression ignition engines

5 S.I. engines are quality-governed engines

The knocking in spark ignition engines can be reduced by

1 Retarding the spark

2 Increasing the engine speed

3 Both (A) and (B)

4 None of these

In a four stroke cycle petrol engine, the compression

1 Starts at 40° after bottom dead centre and ends at 30° before top dead centre

2 Starts at 40° before bottom dead centre and ends at 30° after bottom dead centre

3 Starts at bottom dead centre and ends at top dead centre

4 May start and end anywhere

Pour point of fuel oil is the

1 Minimum 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

2 Temperature at which it solidifies or congeals

3 It catches fire without external aid

4 Indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off