Home
Current Affairs January 2024

What is the correct answer?

4

The cam shaft of a four stroke I.C. engine running at 1500 rpm will run at

A. 1500 rpm

B. 750 rpm

C. 3000 rpm

D. Any value independent of engine speed

Correct Answer :

B. 750 rpm


Related Questions

What is the correct answer?

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

What is the correct answer?

4

The brake power (B.P.) of the engine is given by (where W = Brake load or dead load in newtons, l = Length of arm in metres, N = Speed of engine in r.p.m., S = Spring balance reading in newtons, D = Dia. of brake drum in metres, and d = Dia. of rope in metres)

A. B.P = (Wl × 2πN)/60 watts

B. B.P = [(W - S) πDN]/60 watts

C. B.P = [(W - S) π (D + d) N]/60 watts

D. All of these

What is the correct answer?

4

The brake power of a diesel engine, keeping other parameters constant, can be increased by

A. Decreasing the density of intake air

B. Increasing the temperature of intake air

C. Increasing the pressure of intake air

D. Decreasing the pressure of intake air

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

What is the correct answer?

4

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

What is the correct answer?

4

Which of the following statement is correct?

A. Compression ratio for petrol engines varies from 6 to 10

B. Higher compression ratio in diesel engines results in higher pressures

C. Petrol engines work on Otto cycle

D. All of the above

What is the correct answer?

4

The spark ignition engines are governed by

A. Hit and miss governing

B. Qualitative governing

C. Quantitative governing

D. Combination of (B) and (C)

What is the correct answer?

4

The fuels in order of decreasing knock tendency for spark ignition engines are

A. Paraffin, aromatic, napthene

B. Paraffin, napthene, aromatic

C. Napthene, aromatics, paraffin

D. Napthene, paraffin, aromatic

What is the correct answer?

4

Pre-ignition is caused by the spontaneous combustion of the mixture before the end of the compression stroke, and is due to

A. Cylinder walls being too hot

B. Overheated spark plug points

C. Red hot carbon deposits on cylinder walls

D. Any one of these

What is the correct answer?

4

The air-fuel ratio of the petrol engine is controlled by

A. Carburettor

B. Injector

C. Governor

D. None of these

What is the correct answer?

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%

What is the correct answer?

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

What is the correct answer?

4

A higher compression ratio causes

A. Pre-ignition

B. Increase in detonation

C. Acceleration in the rate of combustion

D. Any one of these

What is the correct answer?

4

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

A. 0

B. 50

C. 100

D. 120

What is the correct answer?

4

In a four stroke cycle petrol engine, the inlet valve

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

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

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

D. May open or close anywhere

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 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 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

What is the correct answer?

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

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

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

A. Decrease

B. Increase

C. Remain same

D. None of these

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 loud pulsating noise heard within the cylinder of an internal combustion engine is known as

A. Detonation

B. Turbulence

C. Pre-ignition

D. Supercharging

What is the correct answer?

4

The reflectivity depends upon

A. Geometry of the reflector

B. Energy of neutrons

C. Properties of the reflector

D. All of these

What is the correct answer?

4

Which of the following is false statement? Excess quantities of sulphur in diesel fuel are Objectionable because it may cause the following

A. Piston ring and cylinder wear

B. Formation of hard coating on piston skirts

C. Oil sludge in the engine crank case

D. Detonation

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

For the same power developed in I.C. engines, the cheaper system is

A. Naturally aspirated

B. Supercharged

C. Centrifugal pump

D. Turbo charger

What is the correct answer?

4

A spark plug gap is kept from

A. 0.3 to 0.7 mm

B. 0.2 to 0.8 mm

C. 0.4 to 0.9 mm

D. 0.6 to 1.0 mm

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

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