Deck 4: Air-Conditioning System Operating Principlesthe Manifold and Gauge Set

Question 1

All of the following statements about the hand valves in an air conditioning gauge manifold are true,EXCEPT:

A) When both hand valves are closed, both the low- and high-side hose ports are connected only to the low- and high-side gauges.
B) If either hand valve is cracked open and the center hose is opened, refrigerant pressure will equalize across the system.
C) The gauges show respective system pressures when the manifold hand valves are closed.
D) If both manifold hand valves are cracked, the pressures will equalize in the manifold and neither of the gauges will accurately indicate system pressure.

Answer 1

B

Question 2

The evaporator is on the low-pressure side of the system.

Answer 2

True

Question 3

The temperature of superheated refrigerant is

A) at its boiling point.
B) above its boiling point.
C) below its boiling point.
D) none of the above.

Answer 3

B

Question 4

The accumulator contains low-pressure vapor.

Question 5

Accumulators are used with expansion valve systems.

Question 6

When relative humidity is high,the air conditioner must work harder than when relative humidity is low.

Question 7

The low-side gauge is capable of reading a vacuum when necessary.

Question 8

When the air conditioning system is operating all of the following happens inside the evaporator,EXCEPT:

A) the refrigerant removes heat from the outside air.
B) the refrigerant changes from a vapor to a liquid.
C) heat entering the refrigerant causes it to change state.
D) the refrigerant absorbs heat.

Question 9

Technician A says the air conditioning system is designed to remove heat from the passenger compartment.Technician B says the air conditioning system is designed to tranfer heat absorbed to the outside air.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 10

The condenser is on the low-pressure side of the system.

Question 11

There is a direct relationship between temperature and pressure in an automotive air conditioning system.

Question 12

The compressor changes a low-pressure vapor to

A) a low-pressure liquid.
B) a high-pressure liquid.
C) a high-pressure vapor.
D) any of the above, depending on the outside air temperature.

Question 13

The refrigerant entering the condenser is in the liquid state.

Question 14

Technician A says there is a common passage on a manifold and gauge set.Technician B says both hand valves on a manifold and gauge set must be closed to read service pressures.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 15

The receiver-dryer is located on the low-pressure side of the system.

Question 16

Technician A says the CFC-12 (R-12)service manifold hose fitting must be 1/2-inch male refrigerant flare nut at each end.Technician B says HFC-134a (R-134a)service manifold hoses use an ACME female nut.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 17

A modern air conditioner system will have either an accumulator or a receiver-drier but not both.

Question 18

On a system that uses an accumuator what type of metering device is used?

A) hot gas bypass
B) thermostatic expansion valve
C) fixed orifice tube
D) suction valve

Question 19

The metering device changes high-pressure liquid to

A) a low-pressure vapor.
B) a low-pressure liquid.
C) a high-pressure liquid.
D) any of the above, depending on the outside air temperature.

Question 20

What affect does the receiver dryer have on the refrigerant?

A) Changes the refrigerant from a liquid to a vapor.
B) Increases the high-side refrigerant pressure.
C) Acts as a storage container for liquid refrigerant.
D) None of the above.

Question 21

All of the following statements about the air conditioning circuit are true,EXCEPT:

A) Heat transfer is accomplished by two pressure and two temperature systems.
B) Any time there is a pressure change, there is a temperature change.
C) A pressure-temperature change can cause a change of state.
D) On the low-pressure side, the change is from a vapor to a liquid.

Question 22

An air conditioning system with an expansion valve will also have a ______.

Question 23

Technician A says the compressor is the dividing line of the refrigeration system,low- to high-side.Technician B says the metering device is the dividing line of the refrigeration system,low- to high-side.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 24

The metering device changes high-pressure liquid into a

A) low-pressure liquid.
B) high-pressure vapor.
C) low-pressure vapor.
D) Any of the above, depending on the outside air temperature.

Question 25

Where in the system is the receiver dryer located?

A) on the inlet to the condenser.
B) on the outlet of the evaporator.
C) on the outlet of the condenser.
D) none of the above.

Question 26

Technician A says that the accumulator is on the high-pressure side of the refrigerant system.Technician B says that the receiver-drier is attached to the evaporator outlet on the refrigerant system.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 27

Technician A says Schrader-type valves on refrigerant system service fittings self-seal when the manifold hoses are removed.Technician B says HFC-134a manifold hoses use quick disconnect couplers for attaching to the refrigerant system service fittings.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 28

Technician A says the Schrader-type service valve is automatically opened when the service hose is installed.Technician B says the Schrader-type service valve is automatically closed when the service hose is removed.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 29

What is the heart of the refrigerant system?

Question 30

What state is the refrigerant in the condenser?

Question 31

What is the function of the refrigerant condenser?

Question 32

What is one of the dividing points between the high and low sides of the refrigerant system?

Question 33

What does the air conditioning compressor do to the system refrigerant?

A) Increases its volatility.
B) Increases its pressure
C) Changes it form a vapor to a liquid.
D) Increases its speed.

Question 34

The basic diagnostic tool used on a refrigerant system is the?

Question 35

Under normal operating conditions all of the following occurs inside the evaporator,EXCEPT:

A) The refrigerant removes heat from the outside air drawn across the evaporator core.
B) The refrigerant changes from a vapor to a liquid.
C) Heat entering the refrigerant causes it to change state.
D) The refrigerant absorbs heat.

Question 36

Performance testing on air conditioning is being discussed.Technician A says the engine should be operated at speeds over 3,000 rpm during the test.Technician B says a fan should be used to force air through the condenser and radiator.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 37

What does the term relative humidity mean?

Question 38

Technician A says that an evaporator is a heat exchanger.Technician B says that a condenser is a heat exchanger.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 39

What are the names of the basic refrigerant system components?

Question 40

What is the drying agent in the receiver-drier or accumulator known as?

Question 41

What is R-134a chemically? It is referred to as what?

Question 42

What is the easiest method of determining if you have an expansion valve/receiver-dryer or an orifice tube/accumulator system?

Question 43

Where is the refrigerant system desiccant located?

Question 44

Explain why high pressure must be maintained in the condenser.

Question 45

What system pressures are on each side of the compressor?

Question 46

Explain why low pressure must be maintained in the evaporator.

Question 47

What component is used and how does liquid refrigerant lower passenger compartment temperature?

Question 48

What is the basic function of the automotive air conditioning system?

Question 49

What is the main chemical advantage of R-134a refrigerant over R-12 refrigerant?

Question 50

What is the heart of the refrigerant system?