Compressors, Gas Turbines and Jet Engines MCQs

Question 1

Gas turbine blades are given a rake

Accepted Answer

In the direction of motion of blades

Answer

Equal to zero

Answer

Opposite to the direction of motion of blades

Answer

Depending on the velocity

Question 2

Rotary compressors are suitable for

Accepted Answer

Large discharge at low pressure

Answer

Large discharge at high pressure

Answer

Low discharge at high pressure

Answer

Low discharge at low pressure

Question 3

An air compressor may be controlled by

Accepted Answer

Any one of the above

Answer

Throttle control

Answer

Clearance control

Answer

Blow off control

Question 4

The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the

Accepted Answer

Total temperature drop in the stage

Answer

Adiabatic temperature drop in the stage

Answer

Total temperature drop

Answer

Total adiabatic temperature drop

Question 5

The net work input required for compressor with increase in clearance volume

Accepted Answer

Remains same

Answer

Increases

Answer

Decreases

Answer

Increases/decreases depending on compressor capacity

Question 6

Volumetric efficiency of a compressor without clearance volume

Accepted Answer

Is not dependent upon compression ratio

Answer

Increases with increase in compression ratio

Answer

Decreases with increase in compression ratio

Answer

May increase/decrease depending on compressor capacity

Question 7

Volumetric efficiency of a compressor with clearance volume

Accepted Answer

Decreases with increase in compression ratio

Answer

Increases with increase in compression ratio

Answer

In not dependent upon compression ratio

Answer

May increase/decrease depending on compressor capacity

Question 8

Compression efficiency is compared against

Accepted Answer

Isothermal compression

Answer

Ideal compression

Answer

Adiabatic compression

Answer

Isentropic compression

Question 9

Phenomenon of choking in compressor means

Accepted Answer

Fixed mass flow rate regardless of pressure ratio

Answer

No flow of air

Answer

Reducing mass flow rate with increase in pressure ratio

Answer

Increased inclination of chord with air steam