Oil Hydraulics and Pneumatics (3151913) MCQs

MCQs of Air Preparation and Service Unit

Showing 11 to 20 out of 48 Questions
1 2 3 4 5
11.

Which factor is/are considered while selecting pneumatic pipes?

(a)

Pressure of compressed air in the line
(b)

Permissible pressure drops in the line
(c)

Length and diameter of tube 
(d)

All of the mentioned 
Answer:

Option (d)

12.

For the economic reasons, total drop of pressure in pneumatic system is kept limited 

(a)

0.1 bar or even less
(b)

0.3 bar or even less
(c)

0.5 bar or even less
(d)

1 bar or even less
Answer:

Option (a)

13.

Which types of contamination are present in a compressed air system?

(a)

Atmospheric dirt
(b)

Water vapour and condensed water
(c)

Micro-organisms
(d)

All of the mentioned 
Answer:

Option (d)

14.

The rotary compressor can be classified as

(a)

displacement compressor
(b)

steady-flow compressor
(c)

both of the mentioned
(d)

none of the mentioned
Answer:

Option (c)

15.

In the steady-flow compressor, compression occurs by

(a)

transfer of kinetic energy
(b)

transfer of potential energy
(c)

trapping air
(d)

all of the mentioned
Answer:

Option (a)

16.

In a displacement compressor, compression occurs by

(a)

transfer of kinetic energy
(b)

transfer of potential energy
(c)

trapping air
(d)

all of the mentioned
Answer:

Option (c)

17.

The rotary positive displacement machines are _______ and compression is _______.

(a)

cooled, isothermal
(b)

uncooled, isothermal
(c)

cooled, adiabatic
(d)

uncooled, adiabatic
Answer:

Option (d)

18.

The Roots blower and vane-type compressor are the types of

(a)

displacement compressor
(b)

steady-flow compressor
(c)

both of the mentioned
(d)

none of the mentioned
Answer:

Option (a)

19.

For a Root blower, as the pressure ratio increases, efficiency ____

(a)

increases
(b)

decreases
(c)

remains constant
(d)

none of the mentioned
Answer:

Option (b)

20.

The vane-type compressor requires ____ the Roots blower.

(a)

equal work input
(b)

more work input
(c)

less work input
(d)

none of the mentioned 
Answer:

Option (c)

Showing 11 to 20 out of 48 Questions
1 2 3 4 5