Home
Current Affairs January 2024

What is the correct answer?

4

In order to eliminate knocking in compression ignition engines, there should be

A. Short delay period

B. Late auto-ignition

C. Low compression ratio

D. High self ignition temperature of fuel

Correct Answer :

A. Short delay period


Related Questions

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 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

A fuel of an octane number rating of 75 matches in knocking intensity as a mixture of

A. 75% iso-octane and 25% normal heptane

B. 75% normal heptane and 25% iso-octane

C. 75% petrol and 25% diesel

D. 75% diesel and 25% petrol

What is the correct answer?

4

Fuel consumption of diesel engines is not guaranteed at one quarter load because at such low loads

A. The friction is high

B. The friction is unpredictable

C. The small difference in cooling water temperature or in internal friction has a disproportionate effect

D. The engine is rarely operated

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

What is the correct answer?

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

What is the correct answer?

4

Alpha-methyl-naphthalene (C₁₁ H₁₀) has a cetane number of

A. 0

B. 50

C. 100

D. 120

What is the correct answer?

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

What is the correct answer?

4

The magneto in an automobile is basically

A. Transformer

B. D.C. generator

C. Capacitor

D. Magnetic circuit

What is the correct answer?

4

The reason for supercharging in any engine is to

A. Increase efficiency

B. Increase power

C. Reduce weight and bulk for a given output

D. Effect fuel economy

What is the correct answer?

4

The reference fuels for knock rating of spark ignition engines would include

A. Iso-octane and alpha-methyl naphthalene

B. Normal octane and aniline

C. Isooctane and normal hexane

D. Normal heptane and isooctane

What is the correct answer?

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

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 specific fuel consumption per B.P. hour for a diesel engine is about

A. 0.2 kg

B. 0.25 kg

C. 0.3 kg

D. 0.35 kg

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

Which of the following fuel detonates readily?

A. Benzene

B. Iso-octane

C. Normal heptane

D. Alcohol

What is the correct answer?

4

Polymerisation is a chemical process in which molecules of a compound become

A. Larger

B. Slowed down

C. Smaller

D. Liquid

What is the correct answer?

4

The ratio of the work obtained at the crankshaft in a given time to the energy supplied during the same time is called

A. Mechanical efficiency

B. Overall efficiency

C. Indicated thermal efficiency

D. Volumetric efficiency

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

Gaseous fuel guarantees are based on

A. Calorific value of oil

B. Low heat value of oil

C. High heat value of oil

D. Mean heat value of oil

What is the correct answer?

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

What is the correct answer?

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)

What is the correct answer?

4

The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

A. 1/2

B. 1

C. 2

D. 4

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

Morse test can be conducted for

A. Petrol engines

B. Diesel engines

C. Multi cylinder engines

D. All of these

What is the correct answer?

4

The power actually developed by the engine cylinder of an I.C. engine is known as

A. Theoretical power

B. Actual power

C. Indicated power

D. None of these

What is the correct answer?

4

The pressure at the end of compression, in petrol engines, is approximately

A. 10 bar

B. 20 bar

C. 25 bar

D. 35 bar

What is the correct answer?

4

The expansion of fuel in a four stroke cycle diesel engine

A. Starts at 15° before top dead centre and ends at 30° after top dead centre

B. Starts at top dead centre and ends at 30° after top dead centre

C. Starts at 15° after top dead centre and ends at 30° before bottom dead centre

D. May start and end anywhere

What is the correct answer?

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

What is the correct answer?

4

Installation of supercharger on a four cycle diesel engine can result in the following percentage increase in power

A. Up to 35%

B. Up to 50%

C. Up to 75%

D. Up to 100%