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# Fuels, Supercharging & Jet Propulsion - MCQ Test 2

## 30 Questions MCQ Test GATE Mechanical (ME) 2022 Mock Test Series | Fuels, Supercharging & Jet Propulsion - MCQ Test 2

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This mock test of Fuels, Supercharging & Jet Propulsion - MCQ Test 2 for Mechanical Engineering helps you for every Mechanical Engineering entrance exam. This contains 30 Multiple Choice Questions for Mechanical Engineering Fuels, Supercharging & Jet Propulsion - MCQ Test 2 (mcq) to study with solutions a complete question bank. The solved questions answers in this Fuels, Supercharging & Jet Propulsion - MCQ Test 2 quiz give you a good mix of easy questions and tough questions. Mechanical Engineering students definitely take this Fuels, Supercharging & Jet Propulsion - MCQ Test 2 exercise for a better result in the exam. You can find other Fuels, Supercharging & Jet Propulsion - MCQ Test 2 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. (d)

QUESTION: 3

### Assertion (A): Octane number is used for rating of fuels in spark ignition engine. Reason (R): Octane number of a fuel is defined as percentage by volume, of iso-octanein a mixture of iso-octane and ex-methylnaphthalene.

Solution:

Ans. (c) Octane number of a fuel is defined as percentage by volume, of iso-octane in a mixture of iso-octane and n-heptane.

QUESTION: 4

Assertion (A): Iso-octane has been chosen as the reference for S.I. engine fuels and hasbeen assigned a value of octane number 100.

Reason (R): Among the fuels, iso-octane ensures the highest compression ratio atwhich an S.I. engine can be operated without knocking.

Solution:

Ans. (a) Both assertion and reason given are true. Also the reason R is the correct
explanation of the assertion.

QUESTION: 5

The Cetane number of automotive diesel fuel used in India is in which one of the following ranges?

Solution:

Ans. (b) Indian Diesel: Year 2000: CN48, Sulfur 0.25%
Year 2010: CN48, sulfur 350PPM will be Euro 3
Note: sulfur 50PPM will be Euro4

QUESTION: 6

Consider the following statements regarding n-Cetane:
1. It is a standard fuel used for knock rating of diesel engines.
2. Its chemical name is n-hexadecane
3. It is a saturated hydrocarbon of paraffin series.
4. It has long carbon chain structure.
Of the above correct statements are

Solution:

Ans. (a)

QUESTION: 7

Consider the following statements:
1. Supercharging increases the power output and increases the volumetricefficiency.
2. Supercharging is more suitable for S.I. engines than C.I. engines.
3. The limit of supercharging for an S.I. engine is set by knock while that for a C.I. engine is set by thermal loading.
Which of the statements given above are correct?

Solution:

Ans. (c) Supercharging is more suitable for C.I. engines than S.I. engines.

QUESTION: 8

Which one of the following types of compressors is mostly used for super charging of I.C. engines?

Solution:

Ans. (c) Roots blower is mostly used for supercharging of I.C. engines

QUESTION: 9

Consider the following statements with reference to supercharging of I.C. engines:
1. Reciprocating compressors are invariably used for high degree of supercharging
2. Rotary compressors like roots blowers are quite suitable for low degree of supercharging
3. Axial flow compressors are most commonly employed for super charging diesel engines used in heavy duty transport vehicles
4. Centrifugal compressors are used for turbo -charging
Which of the statements given above are correct?

Solution:

Ans. (d)

QUESTION: 10

What is the purpose of employing super charging for an engine?

Solution:

Ans. (d)

QUESTION: 11

Which one of the following is correct?The turbine of the turbo-prop engine as compared to that of the turbojetengine is

Solution:

Ans. (c) Though turbo-prop engine used in small aircraft due to its large number of stages its size is Big for same power.

QUESTION: 12

In a turbojet engine, subsequent to heat addition to compressed air, to get the power output, the working substance is expanded in

Solution:

Ans. (b)

QUESTION: 13

Propulsion efficiency of a jet engine is given by (where u is flight velocity andV is jet velocity relative to aircraft).

Solution:

Ans. (c)

QUESTION: 14

Consider the following statements:
In a turbojet engine, thrust may be increased by
1. Increasing the jet velocity
2. Increasing the mass flow a rate of air
3. After burning of the fuel.
Of these statements

Solution:

Ans. (d)

QUESTION: 15

The theoretical mechanical efficiency of a jet engine (neglecting frictional and thermal losses), when driving a vehicle, has its maximum

Solution:

Ans. (c)

QUESTION: 16

The efficiency of jet engine is

Solution:

Ans. (a)

QUESTION: 17

Assertion (A): A bypass jet engine gives a better propulsive efficiency and better fuele conomy than a straight jet engine.
Reason (R): A bypass jet engine gives lower velocity of jet efflux than a straight jet engine.

Solution:

Ans. (a)

QUESTION: 18

In turbo prop, the expansion of gases takes place approximately

Solution:

Ans. (b)

QUESTION: 19

Assertion (A): The use of turboprop engine is limited to medium speed applications.

Reason (R): The efficiency of a turboprop engine decreases at higher speed.

Solution:

Ans. (c) In fact the efficiency increases with speed but thrust keeps on decreasing.

QUESTION: 20

A turbo prop is preferred to turbo-jet because

Solution:

Ans. (d)

QUESTION: 21

Consider the following statements relating to rocket engines:
1. The combustion chamber in a rocket engine is directly analogous to the reservoir of a supersonic wind tunnel.
2. Stagnation conditions exist at the combustion chamber.
3. The exit velocities of exhaust gases are much higher than those in jet engines.
4. Efficiency of rocket engines is higher than that of jet engines.
Of these correct statements are

Solution:

Ans. (c)

QUESTION: 22

Which one of the following is the correct sequence of the position of the givencomponents in a turboprop?

Solution:

Ans. (c)

QUESTION: 23

Assertion (A): Turbojet engine is superior to turboprop engine at all operating conditions.
Reason (R): Efficiency of the propeller is low at high altitude and at high speeds.

Solution:

Ans. (d) A is false but R is true.

QUESTION: 24

Consider the following statements about a rocket engine:
1. It is very simple in construction and operation.
2. It can attain very high vehicle velocity.
3. It can operate for very long duration.
Of these statements

Solution:

Ans. (d) All statements are correct.

QUESTION: 25

Only rocket engines can be propelled to 'SPACE' because

Solution:

Ans. (d) Rocket engines can be propelled to space because they are not air breathing
engines

QUESTION: 26

Assertion (A): Liquid oxygen-liquid hydrogen propellant system has a higher specificimpulse relative to the liquid oxygen-hydrocarbon system.  Reason (R): Hydrogen has a higher burning velocity than hydrocarbons.

Solution:

Ans. (a) Both assertion and reason are true and also R provides correct explanation for A.

QUESTION: 27

In solid propellants rockets, ammonium picrate is usually added as:

Solution:

Ans. (a)

QUESTION: 28

Consider the following statements indicating a comparison between rocket and jet propulsion systems:
1. Both rocket and jet engines carry the fuel and oxidant.
2. Rockets do not employ compressor or propeller.
3. Rockets can operate in vacuum also.
4. Rockets can use solid fuels and oxidants.
Which of the statements given above are correct?

Solution:

Ans. (c) 1 is false, jet engines absorb oxygen from atmosphere.

QUESTION: 29

Assertion (A): A rocket engine can operate even in vacuum and in any fluid medium.

Reason (R): Rocket engine is a pure reaction engine, wherein a propulsive thrust is obtained as a reaction of momentum of ejected matter.

Solution:

Ans. (a) Both A and R are true and R provides correct explanation for A.

QUESTION: 30

Consider the following statements:
The thrust of a rocket engine depends upon
1. Effective jet velocity
2. Weight of the rocket
3. Rate of propellant consumption
Of these statements

Solution:

Ans. (b)