Question 1

What is a key factor when developing a new pneumatic system?

Accepted Answer

Compressor capacity

Answer

Compressor size

Answer

Compressor weight

Answer

Compressor temperature

Question 2

Which compressor is most commonly used in pneumatic systems?

Accepted Answer

Reciprocating-piston compressor

Answer

Sliding-vane compressor

Answer

Axial dynamic compressor

Answer

Centrifugal compressor

Question 3

How does a reciprocating compressor operate?

Accepted Answer

It uses a piston connected to a crankshaft to compress air

Answer

It uses rotating screws to draw in air

Answer

It uses centrifugal force to compress air

Answer

It compresses air using impellers in a diffuser

Question 4

What distinguishes a single-acting compressor from a double-acting compressor?

Accepted Answer

Single-acting compresses air on one side of the piston, double-acting on both sides

Answer

Double-acting uses sliding vanes

Answer

Double-acting has no intake stroke

Answer

Single-acting has two compression strokes per revolution

Question 5

How many intake and compression strokes occur per crankshaft revolution in a double-acting compressor?

Accepted Answer

Two intake and two compression strokes

Answer

Four compression and zero intake

Answer

Two compression and one intake

Answer

One intake and one compression stroke

Question 6

What is the main characteristic of rotary compressors?

Accepted Answer

Continuous rotary motion

Answer

Piston-based compression

Answer

Inlet valve exhaust

Answer

Axial impellers

Question 7

What makes rotary compressors suitable for continuous use?

Accepted Answer

They are not limited by reciprocating motion

Answer

They have fewer moving parts than dynamic compressors

Answer

They require no lubrication

Answer

They rely on start-stop operation

Question 8

Which rotary compressor uses a rotor with vanes that slide in and out?

Accepted Answer

Rotary, sliding-vane compressor

Answer

Lobe-type compressor

Answer

Rotary screw compressor

Answer

Reciprocating-piston compressor

Question 9

Why is oil injected into a rotary sliding-vane compressor?

Accepted Answer

To reduce vane wear and increase sealing

Answer

To add weight to the air

Answer

To remove dust from intake

Answer

To cool the external housing

Question 10

What is a common requirement of sliding-vane compressors for proper operation?

Accepted Answer

High-quality oil lubrication

Answer

Crankshaft balancing

Answer

Inlet fans

Answer

Constant cooling water

Question 11

Which compressor uses two meshing helical screws?

Accepted Answer

Rotary screw compressor

Answer

Lobe-type compressor

Answer

Sliding-vane compressor

Answer

Axial dynamic compressor

Question 12

What makes rotary screw compressors deliver non-pulsating airflow?

Accepted Answer

Their continuous, positive displacement operation

Answer

High-pressure reservoirs

Answer

Piston recoil suppression

Answer

Dual-stage chambers

Question 13

Why are rotary screw compressors preferred for continuous-duty applications?

Accepted Answer

They are designed to operate efficiently under load without stopping

Answer

They can compress liquids

Answer

They never require maintenance

Answer

They are very inexpensive

Question 14

How do dynamic compressors differ from positive-displacement types?

Accepted Answer

They convert kinetic energy into pressure

Answer

They use pistons

Answer

They rely on manual operation

Answer

They compress in pulses

Question 15

What are the two major types of dynamic compressors?

Accepted Answer

Centrifugal and axial

Answer

Piston and screw

Answer

Reciprocating and rotary

Answer

Sliding-vane and lobe

Question 16

What is the function of a diffuser in a centrifugal compressor?

Accepted Answer

It slows down air velocity to increase pressure

Answer

It injects oil into the chamber

Answer

It cools the compressor housing

Answer

It filters incoming air

Question 17

In an axial compressor, what creates pressure?

Accepted Answer

Interaction of rotor and stator blades

Answer

Reciprocating pistons

Answer

Sliding vanes

Answer

Compression chambers

Question 18

Where are the bearings located in most dynamic compressors?

Accepted Answer

Outside the compression chamber

Answer

In the discharge line

Answer

Inside the compression rotor

Answer

Within the impeller

Question 19

What is the benefit of having bearings located outside the compression chamber?

Accepted Answer

No internal lubrication is required

Answer

More weight is added

Answer

Oil can be directly injected

Answer

Less vibration occurs

Question 20

What are lobe-type compressors commonly referred to as?

Accepted Answer

Blowers

Answer

Expanders

Answer

Pushers

Answer

Centrifugal pumps

Question 21

What type of pressure do lobe-type compressors typically provide?

Accepted Answer

Low pressure (10–20 psi)

Answer

High pressure (200+ psi)

Answer

Variable pressure up to 100 psi

Answer

Vacuum only

Question 22

What mechanism moves air in a lobe-type compressor?

Accepted Answer

Two or three-lobed impellers

Answer

Stator blades

Answer

Piston and crank

Answer

Rotating screws

Question 23

What is the purpose of multistage compression?

Accepted Answer

To allow gradual air compression and cooling

Answer

To increase motor torque

Answer

To reduce system size

Answer

To use fewer valves

Question 24

How does staging increase efficiency?

Accepted Answer

By removing heat between compression steps

Answer

By exhausting air before compression

Answer

By bypassing intake air

Answer

By using more oil

Question 25

What component cools compressed air between stages?

Accepted Answer

Intercooler

Answer

Inlet filter

Answer

Oil separator

Answer

Reservoir

Question 26

What is one result of compressing cool air instead of hot air?

Accepted Answer

Less power is required

Answer

Higher backpressure builds

Answer

The system overheats

Answer

More pulsation occurs

Question 27

What is a common two-stage compressor configuration?

Accepted Answer

One low-pressure piston and one high-pressure piston

Answer

One dynamic and one rotary stage

Answer

Two identical high-pressure pistons

Answer

Three low-pressure chambers

Question 28

What is the goal of compressor-capacity control?

Accepted Answer

To match air output with demand

Answer

To keep the compressor always running

Answer

To increase noise

Answer

To limit intake only

Question 29

What happens in a bypass control system when pressure is reached?

Accepted Answer

Air is bypassed back to the intake

Answer

Air is compressed more

Answer

The motor turns off

Answer

The intake valve is closed

Question 30

Why is bypass control inefficient?

Accepted Answer

The compressor runs continuously at full capacity

Answer

It uses too little energy

Answer

Air is cooled too much

Answer

Pressure fluctuates wildly

Question 31

What type of control starts and stops the compressor with a pressure switch?

Accepted Answer

Start-stop control

Answer

Bypass control

Answer

Speed control

Answer

Thermostatic control

Question 32

What determines the compressor's start-stop points?

Accepted Answer

Pressure settings

Answer

Temperature sensors

Answer

Timer delays

Answer

Oil levels

Question 33

What is an important consideration in start-stop control?

Accepted Answer

Minimum pressure must be higher than actuator requirements

Answer

Oil must be bypassed constantly

Answer

The compressor should run continuously

Answer

The motor should stop immediately when demand ends

Question 34

What happens in inlet valve unloading control?

Accepted Answer

The inlet valve stays open, preventing intake compression

Answer

The pressure is bypassed

Answer

The discharge valve opens

Answer

The compressor shuts down

Question 35

How does speed-controlled capacity control adjust air output?

Accepted Answer

By varying motor speed

Answer

By opening a side valve

Answer

By changing discharge temperature

Answer

By increasing oil flow

Question 36

What is a unique way to control compressor capacity?

Accepted Answer

Varying the inlet size

Answer

Adding extra fans

Answer

Changing pipe materials

Answer

Using heavier oil

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