Home
Current Affairs January 2024

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)

Correct Answer :

A. [2(V₀/V₁)]/ [1 + (V₀/V₁)²]


Related Questions

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

In compression ignition engines, swirl denotes a

A. Haphazard motion of the gases in the chamber

B. Rotary motion of the gases in the chamber

C. Radial motion of the gases in the chamber

D. None of the above

What is the correct answer?

4

The function of a distributor in a coil ignition system of I.C. engines is

A. To distribute spark

B. To distribute power

C. To distribute current

D. To time the spark

What is the correct answer?

4

In a four stroke cycle petrol engine, the pressure inside the engine cylinder during the suction stroke is __________ the atmospheric pressure.

A. Equal to

B. Below

C. Above

D. None of these

What is the correct answer?

4

A diesel engine has compression ratio from

A. 6 to 10

B. 10 to 15

C. 15 to 25

D. 25 to 40

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

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

The combustion in compression ignition engines is

A. Homogeneous

B. Heterogeneous

C. Both (A) and (B)

D. None of these

What is the correct answer?

4

The knocking in diesel engines may be prevented by

A. Reducing the delay period

B. Raising the compression ratio

C. Increasing the inlet pressure of air

D. All of these

What is the correct answer?

4

Compression loss in I.C engines occurs due to

A. Leaking piston rings

B. Use of thick head gasket

C. Clogged air inlet slots

D. All of the above

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

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

Scavenging is usually done to increase

A. Thermal efficiency

B. Speed

C. Power output

D. Fuel consumption

What is the correct answer?

4

The basic requirement of a good combustion chamber is

A. Minimum turbulence

B. Low compression ratio

C. High thermal efficiency and power output

D. Low volumetric efficiency

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

Number of working strokes per min. for a four stroke cycle engine are _________ the speed of the engine in r.p.m.

A. Equal to

B. One-half

C. Twice

D. Four-times

What is the correct answer?

4

In petrol engines, the delay period is of the order of

A. 0.001 second

B. 0.002 second

C. 0.003 second

D. 0.004 second

What is the correct answer?

4

Air fuel ratio at which a petrol engine cannot work is

A. 8 : 1

B. 10 : 1

C. 15 : 1

D. 20 : 1 and less

What is the correct answer?

4

The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is

A. Same

B. Less

C. More

D. More or less depending on power rating

What is the correct answer?

4

A diesel engine as compared to petrol engine (both running and rated load) is

A. More efficient

B. Less efficient

C. Equally efficient

D. Other factors will decide it

What is the correct answer?

4

Morse test is used to determine the I.P. of a

A. Single cylinder petrol engine

B. Four stroke engine

C. Single cylinder diesel engine

D. Multi cylinder engine

What is the correct answer?

4

In a coil ignition system of petrol engines, a condenser is connected across the contact breaker in order to

A. Prevent sparking across the gap between the points

B. Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit

C. Both (A) and (B)

D. None of the above

What is the correct answer?

4

The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

A. 4-6 kg/cm² and 200-250°C

B. 6-12 kg/cm² and 250-350°C

C. 12-20 kg/cm² and 350-450°C

D. 20-30 kg/cm² and 450-500°C

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

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

In an internal combustion engine, the process of removing the burnt gases from the combustion chamber of the engine cylinder is known as

A. Scavenging

B. Detonation

C. Supercharging

D. Polymerisation

What is the correct answer?

4

The delay period in compression ignition engines depends upon

A. Temperature and pressure in the cylinder at the time of injection

B. Nature of the fuel mixture strength

C. Relative velocity between the fuel injection and air turbulence pressure of residual gases

D. All of the above

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

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

In petrol engine, using a fixed octane rating fuel and fixed compression ratio, supercharging will _________ the knocking tendency.

A. Not effected

B. Decrease

C. Increase

D. None of these