Mechanical Engineering

Question: In a gas turbine, air is obtained from the atmosphere and compressed in an air compressor.
[A].

True

[B].

False

Answer: Option A

Explanation:

No answer description available for this question.

Question: The basic principle of the rocket propulsion is the same as that of jet propulsion.
[A].

Yes

[B].

No

Answer: Option A

Explanation:

No answer description available for this question.

Question: Only rocket engines can be propelled to space because
[A].

they can generate very high thrust

[B].

they have high propulsion efficiency

[C].

these engines can work on several fuels

[D].

they are not air-breathing engines

Answer: Option D

Explanation:

No answer description available for this question.

Question: Which of the following statement is correct relating to rocket engines ?
[A].

The combustion chamber in a rocket engine is directly analogous to the reservoir of a super sonic wind tunnel

[B].

The stagnation conditions exist at the combustion chamber

[C].

The exit velocities of exhaust gases are much higher than those in jet engine

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: A rocket works with maximum overall efficiency when air-craft velocity is __________ the jet velocity.
[A].

equal to

[B].

one-half

[C].

double

Answer: Option B

Explanation:

No answer description available for this question.

Question: A rocket engine uses __________ for the combustion of its fuel.
[A].

surrounding air

[B].

compressed atmospheric air

[C].

its own oxygen

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: In a turbo jet engine, subsequent to heat addition to compressed air, to get the power output, the working substance is expanded in
[A].

exit nozzle, which is a constant volume process

[B].

exit nozzle, which is essentially an isentropic process

[C].

turbine blades, which is a constant volume process

[D].

turbine blades, which is essentially an isentropic process

Answer: Option D

Explanation:

No answer description available for this question.

Question: In open cycle turbo-jet engines used in military aircraft, reheating the exhaust gas from the turbine by burning, more fuel is used to increase the
[A].

thrust and range of aircraft

[B].

efficiency of the engine

[C].

both (a) and (b)

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: In a jet propulsion unit, the products of combustion after passing through the gas turbine are discharged into
[A].

atmosphere

[B].

vacuum

[C].

discharge nozzle

[D].

back to the compressor

Answer: Option C

Explanation:

No answer description available for this question.

Question: A simple turbo-jet engine is basically a gas turbine engine equipped with a propulsive nozzle and diffuser.
[A].

Agree

[B].

Disagree

Answer: Option A

Explanation:

No answer description available for this question.