Compressors, Gas Turbines and Jet Engines MCQs

Question 1

What will be the volume of air at 327°C if its volume at 27°C is 1.5 m3/mt?

Accepted Answer

3 m3/mt.

Answer

1.5 m3/mt.

Answer

18 m3/mt.

Answer

6 m3/mt.

Question 2

The capacity of a compressor is 5 m/min refers to

Accepted Answer

Free air

Answer

Standard air

Answer

Compressed air

Answer

Compressed air at delivery pressure

Question 3

The thermal efficiency of a gas turbine as compared to a diesel plant is

Accepted Answer

Less

Answer

Same

Answer

More

Answer

Depends on other factors

Question 4

A jet engine has

Accepted Answer

No propeller

Answer

Propeller in front

Answer

Propeller at back

Answer

Propeller on the top

Question 5

Isothermal compression though most efficient, but is not practicable because

Accepted Answer

Compressor has to run at very slow speed to achieve it

Answer

It requires very big cylinder

Answer

It does not increase pressure much

Answer

It is impossible in practice

Question 6

The type of rotary compressor used in aeroplanes, is of

Accepted Answer

Axial flow type

Answer

Centrifugal type

Answer

Radial flow type

Answer

None of these

Question 7

Propulsion efficiency of the following order is obtained in practice

Accepted Answer

60%

Answer

34%

Answer

50%

Answer

72%

Question 8

The maximum delivery pressure in a rotary air compressor is

Accepted Answer

10 bar

Answer

20 bar

Answer

30 bar

Answer

50 bar

Question 9

In a closed cycle gas turbine, the air is compressed

Accepted Answer

Isentropically

Answer

Isothermally

Answer

Polytropically

Answer

None of these