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4

The cetane (C16H34) which is a straight chain paraffin, is assigned a cetane number of

A. 0

B. 50

C. 100

D. 120

Correct Answer :

C. 100


Related Questions

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4

Which of the following is the lightest and most volatile liquid fuel?

A. Diesel

B. Kerosene

C. Fuel oil

D. Gasoline

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4

Which one of the following engines will have heavier flywheel than the remaining ones?

A. 30 kW four-stroke petrol engine running at 1500 r.p.m.

B. 30 kW two-stroke petrol engine running at 1500 r.p.m.

C. 30 kW two-stroke diesel engine running at 750 r.p.m.

D. 30 kW four-stroke diesel engine running at 750 r.p.m.

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4

The combustion in compression ignition engines is

A. Homogeneous

B. Heterogeneous

C. Both (A) and (B)

D. None of these

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4

A carburettor is used to supply

A. Petrol, air and lubricating oil

B. Air and diesel

C. Petrol and lubricating oil

D. Petrol and air

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4

The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be

A. Higher

B. Lower

C. Remain unaffected

D. None of the above

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4

Compression loss in I.C engines occurs due to

A. Leaking piston rings

B. Use of thick head gasket

C. Clogged air inlet slots

D. All of the above

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4

If V₁ is the jet velocity and V₀ is the vehicle velocity, then the propulsive efficiency of a rocket is given by

A. [2(V₀/V₁)]/ [1 + (V₀/V₁)²]

B. (V₀/V₁)/ [1 + (V₀/V₁)²]

C. V₀/(V₀ + V₁)

D. V₁/(V₀ + V₁)

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4

If one cylinder of a diesel engine receives more fuel than the others, then for that cylinder the

A. Exhaust will be smoky

B. Piston rings would stick into piston grooves

C. Engine starts overheating

D. Scavenging occurs

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4

A 5 BHP engine running at full load would consume diesel of the order of

A. 0.3 kg/hr

B. 1 kg/hr

C. 3 kg/hr

D. 5 kg/hr

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4

The thermal efficiency of diesel engines on weak mixtures is

A. Unaffected

B. Lower

C. Higher

D. Dependent on other factors

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4

In a petrol engine, the fuel supplied to the engine cylinder is mixed with required quantity of air and the mixture is ignited with a

A. Fuel pump

B. Fuel injector

C. Spark plug

D. None of these

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4

Scavenging air in diesel engine means

A. Air used for combustion sent under pressure

B. Forced air for cooling cylinder

C. Burnt air containing products of combustion

D. Air used for forcing burnt gases out of engine's cylinder during the exhaust period

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4

Supercharging is the process of

A. Supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

B. Providing forced cooling air

C. Injecting excess fuel for raising more loads

D. Supplying compressed air to remove combustion products fully

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4

The thermal efficiency of a standard Otto cycle for a compression ratio of 5.5 will be

A. 25 %

B. 50 %

C. 70 %

D. 100 %

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4

The scavenging efficiency of a four stroke cycle diesel engine is

A. Below 50%

B. Between 50 and 85%

C. Between 85 and 95%

D. Between 95 and 100%

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4

The maximum propulsive efficiency of a turbojet engine is at a speed of

A. 1000 km/h

B. 2000 km/h

C. 2400 km/h

D. 3000 km/h

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4

Which of the following statement is correct regarding normal cetane?

A. It is a standard fuel used for knock rating of diesel engines

B. Its chemical name is normal hexadecane

C. It has long carbon chain structure

D. All of the above

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4

The normal heptane (C7H16) is given a rating of ________ octane number.

A. 0

B. 50

C. 100

D. 120

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4

The increase in intake temperature of internal combustion engines will _________ efficiency.

A. Have no effect on

B. Increase

C. Decrease

D. None of these

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4

Pick up the wrong statement about supercharging

A. Supercharging reduces knocking in diesel engines

B. There can be limited supercharging in petrol engines because of detonation

C. Supercharging at high altitudes is essential

D. Supercharging results in fuel economy

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4

Diesel as compared to petrol is

A. Highly ignitable

B. More difficult to ignite

C. Less difficult to ignite

D. None of these

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4

In the opposed piston diesel engine, the combustion chamber is located

A. Above the piston

B. Below the piston

C. Between the pistons

D. There is no such criterion

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4

In the crankcase method of scavenging, the air pressure is produced by

A. Supercharger

B. Centrifugal pump

C. Natural aspirator

D. Movement of engine piston

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4

The ratio of the indicated thermal efficiency to the air standard efficiency is known as

A. Mechanical efficiency

B. Overall efficiency

C. Volumetric efficiency

D. Relative efficiency

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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 rating of a diesel engine, with increase in air inlet temperature, will

A. Increase linearly

B. Decrease linearly

C. Increase parabolically

D. Decrease parabolically

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4

In a four stroke cycle diesel engine, the compression

A. Starts at 40° after bottom dead centre and ends at 10° before top dead centre

B. Starts at 40° before top dead centre and ends at 40° after top dead centre

C. Starts at top dead centre and ends at 40° before bottom dead centre

D. May start and end anywhere

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4

Pour point of fuel oil is the

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. 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

The _________ engines can work on very lean mixture of fuel.

A. Spark ignition

B. Compression ignition

C. Both (A) and (B)

D. None of these

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4

If the compression ratio of an engine working on Otto cycle is increased from 5 to 7, the percentage increase in efficiency will be

A. 2 %

B. 4 %

C. 8 %

D. 14 %