Home
Current Affairs January 2024

What is the correct answer?

4

A gas engine has a swept volume of 300 cm3 and clearance volume of 25 cm3. Its volumetric efficiency is 0.88 and mechanical efficiency is 0.90. The volume of the mixture taken in per stroke is

A. 248 cm3

B. 252 cm3

C. 264 cm3

D. 286 cm3

Correct Answer :

C. 264 cm3


Related Questions

What is the correct answer?

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

What is the correct answer?

4

The theoretically correct air fuel ratio for petrol engine is of the order of

A. 6 : 1

B. 9 : 1

C. 12 : 1

D. 15 : 1

What is the correct answer?

4

The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called

A. Net efficiency

B. Efficiency ratio

C. Relative efficiency

D. Overall efficiency

What is the correct answer?

4

In case of gas turbines, the gaseous fuel consumption guarantees are based on

A. High heat value

B. Low heat value

C. Net calorific value

D. Calorific value

What is the correct answer?

4

In order to prevent knocking in spark ignition engines, the charge away from the spark plug should have

A. Low density

B. Low temperature

C. Long ignition delay

D. All of these

What is the correct answer?

4

Engine pistons are usually made of aluminium alloy because it

A. Is lighter

B. Wear is less

C. Absorbs shocks

D. Is stronger

What is the correct answer?

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

What is the correct answer?

4

A diesel engine is _________ as compared to petrol engine, both running at rated load.

A. Equally efficient

B. Less efficient

C. More efficient

D. None of these

What is the correct answer?

4

The operation of forcing additional air under pressure in the engine cylinder is known as

A. Scavenging

B. Turbulence

C. Supercharging

D. Pre-ignition

What is the correct answer?

4

The ignition quality of diesel oil is expressed by

A. Cetane number

B. Octane number

C. Calorific value

D. None of these

What is the correct answer?

4

Supercharging is the process of supplying the intake air to the engine cylinder at a density _________ the density of the surrounding atmosphere.

A. Equal to

B. Less than

C. Greater than

D. None of these

What is the correct answer?

4

For maximum power generation, the air fuel ratio for a petrol engine for vehicles, is of the order of

A. 9 : 1

B. 12 : 1

C. 15 : 1

D. 18 : 1

What is the correct answer?

4

Which of the following statement is wrong?

A. A four stroke cycle engine develops twice the power as that of a two stroke cycle engine

B. For the same power developed, a four stroke cycle engine is lighter, less bulky and occupies less floor area

C. The petrol engines are costly than diesel engines

D. All of the above

What is the correct answer?

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

What is the correct answer?

4

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

A. Diesel

B. Kerosene

C. Fuel oil

D. Gasoline

What is the correct answer?

4

The brake power is the power available

A. In the engine cylinder

B. At the crank shaft

C. At the crank pin

D. None of these

What is the correct answer?

4

A stoichiometric air-fuel ratio is

A. Chemically correct mixture

B. Lean mixture

C. Rich mixture for idling

D. Rich mixture for over loads

What is the correct answer?

4

The thermal efficiency of diesel engines on weak mixtures is

A. Unaffected

B. Lower

C. Higher

D. Dependent on other factors

What is the correct answer?

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

What is the correct answer?

4

The theoretically correct mixture of air and petrol is

A. 10 : 1

B. 15 : 1

C. 20 : 1

D. 25 : 1

What is the correct answer?

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

What is the correct answer?

4

In a four stroke cycle diesel engine, the inlet valve

A. Opens at 20° before top dead centre and closes at 40° after bottom dead centre

B. Opens at 20° after top dead centre and closes at 20° before bottom dead centre

C. Opens at top dead centre and closes at bottom dead centre

D. May open and close anywhere

What is the correct answer?

4

Which of the following fuel has little tendency towards detonation?

A. Benzene

B. Iso-octane

C. Normal heptane

D. Alcohol

What is the correct answer?

4

A heat engine utilises the

A. Calorific value of oil

B. Low heat value of

C. High heat value of oil

D. Mean heat value of oil

What is the correct answer?

4

Stoichiometric ratio is

A. Chemically correct air-fuel ratio by weight

B. Chemically correct air-fuel ratio by volume

C. Actual air-fuel ratio for maximum efficiency

D. None of the above

What is the correct answer?

4

A diesel engine has

A. 1 valve

B. 2 valves

C. 3 valves

D. 4 valves

What is the correct answer?

4

The compensating jet in a carburettor supplies almost constant amount of petrol at all speeds because the

A. Jet area is automatically varied depending on the suction

B. The flow from the main jet is diverted to the compensating jet with increase in speed

C. The diameter of the jet is constant and the discharge coefficient is invariant

D. Flow is produced due to the static head in the float chamber

What is the correct answer?

4

The mean effective pressure obtained from engine indicator indicates the

A. Maximum pressure developed

B. Minimum pressure

C. Instantaneous pressure at any instant

D. Average pressure

What is the correct answer?

4

The increase of efficiency of a compression ignition engine, as the load decreases, is due to

A. Higher maximum temperature

B. Qualitative governing

C. Quantitative governing

D. Hit and miss governing

What is the correct answer?

4

The advancing of spark timing in spark ignition engines will _________ knocking tendency.

A. Increase

B. Reduce

C. Not effect

D. None of these