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# Test: Fuels, Supercharging & Jet Propulsion - 1

## 20 Questions MCQ Test RRB JE for Mechanical Engineering | Test: Fuels, Supercharging & Jet Propulsion - 1

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This mock test of Test: Fuels, Supercharging & Jet Propulsion - 1 for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. This contains 20 Multiple Choice Questions for Mechanical Engineering Test: Fuels, Supercharging & Jet Propulsion - 1 (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Fuels, Supercharging & Jet Propulsion - 1 quiz give you a good mix of easy questions and tough questions. Mechanical Engineering students definitely take this Test: Fuels, Supercharging & Jet Propulsion - 1 exercise for a better result in the exam. You can find other Test: Fuels, Supercharging & Jet Propulsion - 1 extra questions, long questions & short questions for Mechanical Engineering on EduRev as well by searching above.
QUESTION: 1

Solution:

Ans. (a)

QUESTION: 2

Solution:

Ans. (b)

QUESTION: 3

### Which one of the following fuels can be obtained by fermentation of vegetable matter?

Solution:

Ans. (d)

QUESTION: 4

Consider the following statements regarding knock rating of SI engine fuels:
1. Iso-octane is assigned a rating of zero octane number.
2. Normal heptane is assigned a rating of hundred octane number
3. Iso-octane is assigned a rating of hundred octane number
4. Normal heptane is assigned a rating of zero octane number
Which of the above statements are correct?

Solution:

Ans. (c)

QUESTION: 5

Reference fuels for knock rating of SI engine fuels would include

Solution:

Ans. (d) Reference fuel for knock rating of SI engine fuels would include n-heptane and isooctane.

QUESTION: 6

The two reference fuels used for cetane rating are

Solution:

Ans. (d) Two reference fuels for cetane rating are cetane and α -methyl naphthalene.

QUESTION: 7

Consider the following statements
1. Motor gasoline is a mixture of various hydrocarbons with a major proportion being aromatic hydrocarbons.
2. Compressed natural gas is mainly composed of methane.
3. Producer gas has a predominant component of hydrogen with lesser proportion of carbon monoxide.
4. Cetane number of fuel used in diesel engines in India is in the range of 80 to 90.
Which of these statements are correct?

Solution:

Ans. (a) Cetane number of fuel used in diesel engines in India is in the range of 55 to 65

QUESTION: 8

What is the main objective of supercharging of the engine?

Solution:

Ans. (d) All of the above are objective of supercharging. But main objective is to increase the power output of engine.

QUESTION: 9

Consider the following statements:
1. Supercharging increases the power output of an engine.
2. Supercharging increases the brake thermal efficiency considerably.
3. Supercharging helps scavenging of cylinders.
Which of the statements given above are correct?

Solution:

Ans. (d)

QUESTION: 10

Surging basically implies

Solution:

Ans. (a)

QUESTION: 11

Assertion (A): The CI engine is basically more suitable for supe rcharging than the SI engine.
Reason (R): In the CI engine super charging tends to prevent diesel knocking.

Solution:

Ans. (a)

QUESTION: 12

Consider the following statements:

In open cycle turbo-jet engines used in military aircraft, reheating theexhaust gas from the turbine by burning more fuel is used to increase.

1. Thrust
2. The efficiency of engine
3. The range of aircraft.

correct statements are

Solution:

Ans. (b)

QUESTION: 13

Assertion (A): Compared to a turbo-jet engine, a turbo-prop engine has a higher power for take-off and higher propulsive efficiency at low speeds.
Reason (R): By mounting the propeller on the turbine shaft, the propeller can be runat a very high speed to obtain higher efficiency.

Solution:

Ans. (c)

QUESTION: 14

Assertion (A): In the subsonic range the propulsive efficiency of a rocket is less thanthat of a turbojet.
Reason (R): The jet velocity of rocket is independent of forward motion.

Solution:

Ans. (b) Both A and R are true but R is not correct explanation of A.

QUESTION: 15

For a jet propulsion unit, ideally the ratio of compressor work and turbinework is

Solution:

Ans. (b)

QUESTION: 16

Assertion (A): After burning increases the thrust of a jet engine.

Reason (R): The air fuel ratio of jet engine is high.

Solution:

Ans. (b)

QUESTION: 17

Consider the following statements regarding performance of turbojet engines:
1. The thrust decreases at higher altitude due to reduced density of air and consequently lower mass flow of air.
2 At subsonic speeds, the effect of increased velocity is to increase the air flow and the thrust increases.
3. The relative velocity of jet with respect to the medium decreases at higher speeds which tends to reduce the thrust.
4 For turbojet engine the thrust of jet at subsonic speeds remains relatively constants.
Which of the statements given above are correct?

Solution:

Ans. (d) The turbojet is almost a constant thrust engine.

QUESTION: 18

Assertion (A): Propulsion efficiency of propeller driven aircraft is low at very highspeeds.

Reason (R): At high speeds, shock waves are formed over propeller blades.

Solution:

Ans. (a)

QUESTION: 19

The thrust of a jet propulsion power unit can be increased by

Solution:

Ans. (a) The thrust of a jet propulsion power unit can be increased by injecting water into the compressor.

QUESTION: 20

Consider the following statements:
As compared to a turboprop, a turbojet
1. Can operate at higher altitudes
2. Can operate at higher flight velocities
3. Is more fuel efficient at lower speeds
Of these statements

Solution:

Ans. (b)