Compressors, Gas Turbines and Jet Engines MCQs

Question 1

Stalling of blades in axial flow compressor is the phenomenon of

Accepted Answer

Air stream not able to follow the blade contour

Answer

Air stream blocking the passage

Answer

Motion of air at sonic velocity

Answer

Unsteady periodic and reversed flow

Question 2

A rocket engine uses __________ for the combustion of its fuel.

Accepted Answer

Its own oxygen

Answer

Surrounding air

Answer

Compressed atmospheric air

Answer

None of these

Question 3

Separators in compressor installations are located

Accepted Answer

Between after-cooler and air receiver

Answer

Before inter-cooler

Answer

After inter-cooler

Answer

After receiver

Question 4

Mechanical efficiency of gas turbines as compared to I.C. engines is

Accepted Answer

Higher

Answer

Lower

Answer

Same

Answer

None of the above

Question 5

The maximum combustion pressure in gas turbine as compared to I.C. engine is

Accepted Answer

Less

Answer

More

Answer

Same

Answer

Depends on other factors

Question 6

Which of the following fuels can be used in turbojet engines?

Accepted Answer

Kerosene

Answer

Liquid hydrogen

Answer

High speed diesel oil

Answer

Methyl alcohol

Question 7

Ram compression in turbojet involves

Accepted Answer

Reduction of speed of incoming air and conversion of part of it into pressure energy

Answer

Compression of inlet air

Answer

Increasing speed of incoming air

Answer

Lost work

Question 8

Standard air is the air at ________ and relative humidity of 36 percent.

Accepted Answer

1 bar and 20°C

Answer

0.1 bar and 20°C

Answer

0.1 bar and 40°C

Answer

1 bar and 40°C

Question 9

Which of the following statement is correct as regard to centrifugal compressors?

Accepted Answer

The static pressure of air in the impeller increases in order to provide centripetal force on the air

Answer

The flow of air is parallel to the axis of the compressor

Answer

The impeller rotates at high speeds

Answer

The maximum efficiency is higher than multistage axial flow compressors