If the compression ratio in I.C. engine increases, then its thermal efficiency will

The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be

A

More

B

Less

C

Same

D

Data insufficient to predict

The thermal efficiency of a diesel cycle having fixed compression ratio, with increase in cut-off ratio will

A

Increase

B

Decrease

C

Be independent

D

May increase or decrease depending on other factors

There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would

A

Remain same

B

Decrease

C

Increase

D

None of the above

In practice, the compression ratio of compression-ignition (CI) engine ranges from

A

15 to 25

B

5 to 10

C

40 to 55

D

60 to 70

Thermal efficiency of a two stroke cycle engine is _________ a four stroke cycle engine.

A

Equal to

B

Less than

C

Greater than

D

None of these

The thermal efficiency of a petrol engine is _________ as compared to diesel engine.

A

Same

B

Less

C

More

D

None of these

Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle

A

Heat rejection is lower

B

Expansion and compression are isentropic

C

Combustion is at constant volume

D

Maximum temperature is higher

With increase in compression ratio, the efficiency of the otto engine

A

Increases

B

Decreases

C

Remains constant

D

Increases linearly

The compression ratio in petrol engine is kept less than in Diesel engine because

A

It makes petrol engines lighter

B

Higher or equivalent compression ratio in petrol engines is not possible due to pre-ignition

C

Less compression ratio gives better performance

D

It is just customary to have less compression ratio in petrol engines

Highest useful compression ratio (HUCR) is the highest compression ratio at which the

A

Engine can run

B

Engine gives maximum output

C

Engine is most efficient

D

Fuel can be used in a test engine without knocking

If the compression ratio in I.C. engine increases, then its thermal efficiency will

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