Home
Current Affairs January 2024

What is the correct answer?

4

The exhaust valve in a four stroke cycle petrol engine

A. Opens at 50° before bottom dead centre and closes at 15° after top dead centre

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

C. Opens at 50° after bottom dead centre and closes at 15° before top dead centre

D. May open and close anywhere

Correct Answer :

A. Opens at 50° before bottom dead centre and closes at 15° after top dead centre


Related Questions

What is the correct answer?

4

In a four stroke cycle petrol engine, the charge is ignited at

A. 30° before top dead centre

B. 30° after top dead centre

C. 30° before bottom dead centre

D. 30° after bottom dead centre

What is the correct answer?

4

The self ignition temperature of petrol is ________ as compared to diesel oil.

A. Same

B. Lower

C. Higher

D. None of these

What is the correct answer?

4

As a result of detonation in an I.C. engine, following parameter attains very high value

A. Peak pressure

B. Rate of rise of pressure

C. Rate of rise of temperature

D. Peak temperature

What is the correct answer?

4

The fuel valve in a four stroke cycle diesel engine

A. Opens at 15° after top dead centre and closes at 20° before bottom dead centre

B. Opens at 15° before top dead centre and closes at 20° after top 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

The sensing element in the control system of nuclear reactors measures the _________ of the neutron flux in the reactor.

A. Temperature

B. Volume

C. Density

D. None of these

What is the correct answer?

4

The probability of knocking in diesel engines is increased by

A. High self ignition temperature

B. Low volatility

C. Higher viscosity

D. All of these

What is the correct answer?

4

The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is

A. Same

B. More

C. Less

D. Less or more depending on operating conditions

What is the correct answer?

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

What is the correct answer?

4

The frictional power (F.P.) is given by

A. F.P. = B.P. - I.P.

B. F.P. = I.P. - B.P.

C. F.P. = B.P./I.P.

D. F.P. = I.P./B.P.

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

In a petrol engine, if diesel is used, then the engine will

A. Not run

B. Run more efficiently

C. Run at high speed

D. Explode

What is the correct answer?

4

Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged?

A. Yes

B. No

C. To some extent

D. Unpredictable

What is the correct answer?

4

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

A. Same

B. Less

C. More

D. None of these

What is the correct answer?

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

What is the correct answer?

4

As compared to air standard cycle, in actual working, the effect of variation in specific heats is to

A. Increase maximum pressure and maximum temperature

B. Reduce maximum pressure and maximum temperature

C. Increase maximum pressure and decrease maximum temperature

D. Decrease maximum pressure and increase maximum temperature

What is the correct answer?

4

The thermal efficiency of diesel engines is about

A. 15 %

B. 30 %

C. 50 %

D. 70 %

What is the correct answer?

4

In loop scavenging, the top of the piston is

A. Flat

B. Contoured

C. Slanted

D. Depressed

What is the correct answer?

4

Which of the following fuel detonates readily?

A. Benzene

B. Iso-octane

C. Normal heptane

D. Alcohol

What is the correct answer?

4

Diesel fuel, compared to petrol is

A. Less difficult to ignite

B. Just about the same difficult to ignite

C. More difficult to ignite

D. Highly ignitable

What is the correct answer?

4

The ignition of the charge by some hot surface within the engine before the passage of spark is called

A. Pre-ignition

B. Detonation

C. Ignition delay

D. Auto-ignition

What is the correct answer?

4

All heat engines utilize

A. Low heat value of oil

B. High heat value of oil

C. Net calorific value of oil

D. Calorific value of fuel

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

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

What is the correct answer?

4

The pressure at the end of compression in the case of diesel engine is of the order of

A. 6 kg/cm

B. 12 kg/cm

C. 20 kg/cm

D. 35 kg/cm

What is the correct answer?

4

The inlet value of a four stroke cycle I.C engine remains open for nearly

A. 180°

B. 125°

C. 235°

D. 200°

What is the correct answer?

4

The thermal efficiency of petrol and gas engines is about

A. 15 %

B. 30 %

C. 50 %

D. 70 %

What is the correct answer?

4

A mixture containing 65% of iso-octane and 35% of normal heptane will have

A. Cetane number 65

B. Octane number 65

C. Cetane number 35

D. Octane number 35

What is the correct answer?

4

The correct mixture strength (by weight) for petrol is about

A. 14.6 : 1

B. 18.5 : 1

C. 20.4 : 1

D. 22.6 : 1

What is the correct answer?

4

If petrol is used in a diesel engine, then

A. Low power will be produced

B. Efficiency will be low

C. Higher knocking will occur

D. Black smoke will be produced

What is the correct answer?

4

Compression ratio of I.C. Engines is

A. The ratio of volumes of air in cylinder before compression stroke and after compression stroke

B. Volume displaced by piston per stroke and clearance volume in cylinder

C. Ratio of pressure after compression and before compression

D. Swept volume/cylinder volume