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4

If the speed of the engine is increased, the indicated power will

A. Increase

B. Decrease

C. Remain same

D. None of these

Correct Answer :

A. Increase


Related Questions

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4

Detonation is harmful due to

A. Increase in the rate of heat transfer, there is a reduction in the power output and efficiency of the engine

B. Excessive turbulence which removes most of the insulating gas boundary layer from the cylinder walls

C. High intensity of knock causes crankshaft vibration and the engine runs rough

D. None of the above

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4

Flash point of fuel oil is

A. 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

B. Temperature at which it solidifies or congeals

C. Temperature at which it catches fire without external aid

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

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4

In a diesel engine, the fuel is ignited by

A. Spark

B. Injected fuel

C. Heat resulting from compressing air that is supplied for combustion

D. Ignition

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4

The air standard efficiency of an I.C. engine is given by (where r = Compression ratio, and γ = Ratio of specific heats)

A. 1 - rγ - 1

B. 1 + rγ - 1

C. 1 - (1/rγ - 1)

D. None of these

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4

Which of the following does not relate to a compression ignition engine?

A. Fuel pump

B. Fuel injector

C. Governor

D. Carburettor

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4

The inlet valve of a four stroke cycle internal combustion engine remains open for

A. 130°

B. 180°

C. 230°

D. 270°

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4

Number of working strokes per min. for a two stroke cycle engine is _________ the speed of the engine in r.p.m.

A. Equal to

B. One-half

C. Twice

D. Four-times

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4

The compression ignition engines are governed by

A. Hit and miss governing

B. Qualitative governing

C. Quantitative governing

D. Combination of (B) and (C)

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4

The mechanical efficiency (ηm) of the engine is given by

A. ηm = B.P/I.P

B. ηm = I.P/B.P

C. ηm = (B.P × I.P)/100

D. None of these

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4

If the temperature of intake air in internal combustion engine increases, then its efficiency will

A. Remain same

B. Decrease

C. Increase

D. None of these

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4

The cetane number of diesel oil, generally available, is

A. 20 to 25

B. 25 to 30

C. 30 to 40

D. 40 to 55

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4

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

A. It is properly designed

B. Best quality fuel is used

C. Cannot work as it is impossible

D. Flywheel size is proper

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4

Alpha-methyl-naphthalene (C₁₁ H₁₀) has a cetane number of

A. 0

B. 50

C. 100

D. 120

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4

The knocking in spark ignition engines can be reduced by

A. Retarding the spark

B. Increasing the engine speed

C. Both (A) and (B)

D. None of these

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4

The thermal efficiency of diesel engines is about

A. 15 %

B. 30 %

C. 50 %

D. 70 %

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4

The magneto in an automobile is basically

A. Transformer

B. D.C. generator

C. Capacitor

D. Magnetic circuit

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4

The fuel in diesel engine is normally injected at pressure of

A. 5-10 kg/cm²

B. 20-25 kg/cm²

C. 60-80 kg/cm²

D. 90-130 kg/cm²

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4

The theoretically correct mixture of air and petrol is

A. 10 : 1

B. 15 : 1

C. 20 : 1

D. 25 : 1

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4

Iso-octane (C8H18) has octane number of

A. 0

B. 50

C. 100

D. 120

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4

Which is more viscous lube oil?

A. SEA 30

B. SAE 50

C. SAE 70

D. SAE 80

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4

Solid fuel fabricated into various small shapes, which are assembled to form fuel elements, is in the form of

A. Plates

B. Pallets

C. Pins

D. All of these

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4

The knock in diesel engine occurs due to

A. Instantaneous and rapid burning of the first part of the charge

B. Instantaneous auto ignition of last part of charge

C. Delayed burning of the first part of the charge

D. Reduction of delay period

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4

The size of inlet valve of an engine in comparison to exhaust valve is

A. More

B. Less

C. Same

D. More/less depending on capacity of engine

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4

The colour of exhaust from diesel engine is generally

A. White

B. Bluish

C. Black

D. Violet

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4

The two reference fuels used for cetane rating are

A. Cetane and iso-octane

B. Cetane and alpha-methyl naphthalene

C. Cetane and normal heptane

D. Cetane and tetra ethyl lead

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4

The pressure at the end of compression, in diesel engines, is approximately

A. 10 bar

B. 20 bar

C. 25 bar

D. 35 bar

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4

The knocking tendency in spark ignition engines may be decreased by

A. Controlling the air-fuel mixture

B. Controlling the ignition timing

C. Controlling the exhaust temperature

D. Reducing the compression ratio

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4

The specific fuel consumption per B.P. hour for a diesel engine is about

A. 0.2 kg

B. 0.25 kg

C. 0.3 kg

D. 0.35 kg

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4

The object of supercharging the engine is

A. To reduce mass of the engine per brake power

B. To reduce space occupied by the engine

C. To increase the power output of an engine when greater power is required

D. All of the above

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4

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

A. 0.15 kg

B. 0.2 kg

C. 0.25 kg

D. 0.3 kg