HVAC Repair Online Quiz: Test Your Knowledge

Question 1

What is the primary function of the compressor in an HVAC unit?

Accepted Answer

Pumping refrigerant

Answer

Cooling the air

Answer

Condensing the refrigerant

Answer

Controlling airflow

Question 2

Which type of refrigerant is commonly utilized in automotive air conditioning systems?

Accepted Answer

R-134a

Answer

R-12

Answer

R-410A

Answer

R-600a

Question 3

What is the condenser's purpose in an air conditioning system?

Accepted Answer

Absorbing heat from the refrigerant

Answer

Liquefying the refrigerant

Answer

Expanding the refrigerant into a gas

Answer

Storing the refrigerant

Question 4

Which component of an air conditioning system is responsible for cooling the air?

Accepted Answer

Evaporator

Answer

Condenser

Answer

Compressor

Answer

Expansion valve

Question 5

What tool is typically used to verify an air conditioning system's pressure?

Accepted Answer

Manifold gauge set

Answer

Multimeter

Answer

Ammeter

Answer

Tachometer

Question 6

Which tool is used to measure the temperature of HVAC system components?

Accepted Answer

Infrared thermometer

Answer

Multimeter

Answer

Tachometer

Answer

Pressure gauge

Question 7

What is the function of an expansion valve in an air conditioning system?

Accepted Answer

Regulating refrigerant flow

Answer

Filtering the refrigerant

Answer

Controlling compressor speed

Answer

Storing the refrigerant

Question 8

In HVAC repair, safety precautions are crucial because they primarily:

Accepted Answer

Protect against electrical hazards and other risks

Answer

Prevent legal issues

Answer

Ensure successful repairs

Answer

Prevent equipment damage

Question 9

Which component is not considered a core component of an HVAC system?

Accepted Answer

Thermostat

Answer

Compressor

Answer

Condenser

Answer

Evaporator

Question 10

Which component in an HVAC system releases heat into the environment?

Accepted Answer

Condenser

Answer

Evaporator

Answer

Compressor

Answer

Expansion valve

Question 11

Which refrigerant is a common alternative to R-12 in automotive air conditioning systems?

Accepted Answer

R-134a

Answer

R-22

Answer

R-410A

Answer

R-507

Question 12

What is the primary function of an evaporator in an HVAC system?

Accepted Answer

To cool the air

Answer

To heat the air

Answer

To circulate the air

Answer

To remove moisture from the air

Question 13

Which component in an HVAC system senses changes in temperature and signals the system to turn on or off?

Accepted Answer

Thermostat

Answer

Sensor

Answer

Controller

Answer

Relay

Question 14

Which tool is used to measure the electrical current in an HVAC circuit?

Accepted Answer

Multimeter

Answer

Manometer

Answer

Ohmmeter

Answer

Tachometer

Question 15

What is a common cause of low refrigerant levels in an HVAC system?

Accepted Answer

Leaks

Answer

Overcharging

Answer

Contamination

Answer

Improper installation

Question 16

Which type of compressor is known for its compact design and high efficiency?

Accepted Answer

Scroll compressor

Answer

Reciprocating compressor

Answer

Centrifugal compressor

Answer

Axial compressor

Question 17

What is the purpose of a capillary tube in an HVAC system?

Accepted Answer

To restrict the flow of refrigerant

Answer

To filter impurities from the refrigerant

Answer

To circulate the refrigerant

Answer

To condense the refrigerant

Question 18

Which component in an HVAC system is responsible for removing moisture from the refrigerant?

Accepted Answer

Receiver-drier

Answer

Filter

Answer

Accumulator

Answer

Evaporator

Question 19

Which of the following is an environmentally responsible practice when handling and disposing of refrigerants?

Accepted Answer

Follow established protocols to reduce refrigerant emissions during servicing.

Answer

Discard refrigerants in regular trash containers.

Answer

Use refrigerant alternatives with higher ozone depletion potential.

Answer

Release refrigerants directly into the atmosphere.

Question 20

The compressor in an HVAC system primarily functions to:

Accepted Answer

Circulate refrigerant through the system

Answer

Extract heat from the air

Answer

Add heat to the air

Answer

Condense refrigerant

Question 21

In automotive air conditioning systems, the most commonly used refrigerant is:

Accepted Answer

R-134a

Answer

R-12

Answer

R-410A

Answer

R-22

Question 22

The purpose of the expansion valve in an HVAC system is to:

Accepted Answer

Control refrigerant flow

Answer

Compress refrigerant

Answer

Condense refrigerant

Answer

Evaporate refrigerant

Question 23

To measure the pressure of refrigerant in an HVAC system, the appropriate tool to use is a:

Accepted Answer

Pressure gauge

Answer

Multimeter

Answer

Vacuometer

Answer

Leak detector

Question 24

A common indication of a faulty condenser in an HVAC system is:

Accepted Answer

Reduced cooling efficiency

Answer

Increased noise levels

Answer

Engine overheating

Answer

Illuminated check engine light

Question 25

Which of the following is not a potential cause of a clogged evaporator in an HVAC system?

Accepted Answer

Adequate air flow

Answer

Accumulation of dirt and debris

Answer

Frozen refrigerant

Answer

Oversized expansion valve

Question 26

In the refrigeration cycle, which component changes high-pressure liquid refrigerant into a low-pressure gas?

Accepted Answer

Evaporator

Answer

Condenser

Answer

Compressor

Answer

Expansion valve

Question 27

Which of these is NOT a typical component of an HVAC system?

Accepted Answer

Battery

Answer

Compressor

Answer

Condenser

Answer

Evaporator

Question 28

Which tool is specifically designed to measure the temperature and pressure of refrigerant in an HVAC system?

Accepted Answer

Refrigerant gauge

Answer

Multimeter

Answer

Thermometer

Answer

Manometer

Question 29

In an air conditioning system, what is the primary function of the condenser?

Accepted Answer

To dissipate heat from the refrigerant

Answer

To filter the refrigerant

Answer

To circulate the refrigerant

Answer

To cool the refrigerant

Question 30

Which refrigerant is widely used in modern automotive air conditioning systems due to its environmental friendliness?

Accepted Answer

R-134a

Answer

R-12

Answer

R-22

Question 31

What is the main purpose of the expansion valve in an HVAC system?

Accepted Answer

To regulate the flow of refrigerant into the evaporator

Answer

To condense the refrigerant

Answer

To increase the pressure of the refrigerant

Answer

To filter impurities from the refrigerant

Question 32

What is the primary function of a capacitor in an HVAC system?

Accepted Answer

To enhance the starting torque of the motor

Answer

To filter electrical noise

Answer

To regulate voltage

Answer

To store electrical energy

Question 33

In an air conditioning system, what is the primary function of the evaporator coil?

Accepted Answer

To absorb heat from the indoor air

Answer

To condense the refrigerant

Answer

To release heat into the outdoor air

Answer

To circulate the refrigerant

Question 34

Which refrigerant is commonly used in automotive air conditioning systems?

Accepted Answer

R134a

Answer

R410a (used in residential HVAC systems)

Answer

R22 (being phased out due to environmental concerns)

Answer

R404a (used in commercial refrigeration)

Question 35

What is the role of a condenser in an automotive air conditioning system?

Accepted Answer

Convert refrigerant from a gas to a liquid

Answer

Filter the refrigerant (performed by the receiver drier)

Answer

Circulate the refrigerant (performed by the compressor)

Answer

Cool the refrigerant (performed by the evaporator)

Question 36

Which symptom indicates a potential issue with the compressor in an automotive air conditioning system?

Accepted Answer

Insufficient cooling

Answer

Refrigerant leaks (can be caused by multiple components)

Answer

Electrical problems (can also affect other components)

Answer

Excessive noise (can also be caused by other components, such as the blower motor)

Question 37

What is the purpose of an expansion valve in an automotive air conditioning system?

Accepted Answer

Regulate the flow of refrigerant into the evaporator

Answer

Filter the refrigerant (performed by the receiver drier)

Answer

Convert refrigerant from a liquid to a gas (performed by the evaporator)

Answer

Lubricate the compressor (performed by the compressor oil)

Question 38

Which diagnostic tool is commonly used to detect leaks in an automotive air conditioning system?

Accepted Answer

UV light and fluorescent dye

Answer

Multimeter (used for electrical testing)

Answer

Vacuum pump (used for evacuating the system)

Answer

Pressure gauges (used for system pressure testing)

Question 39

What is the recommended torque range for refrigerant line fittings on an automotive air conditioning system?

Accepted Answer

60-80 ft-lbs

Answer

40-50 ft-lbs (within the acceptable range, but lower than recommended)

Answer

20-30 ft-lbs (too low, may cause leaks)

Answer

100-120 ft-lbs (excessively high, can damage fittings)

Question 40

What is the primary function of an accumulator in an automotive air conditioning system?

Accepted Answer

Store excess refrigerant during system operation

Answer

Filter the refrigerant (performed by the receiver drier)

Answer

Regulate the flow of refrigerant (performed by the expansion valve)

Answer

Cool the compressor (performed by the condenser)

Question 41

Which of the following is a common cause of poor airflow from the vents in an automotive HVAC system?

Accepted Answer

Clogged cabin air filter

Answer

Dirty evaporator coil (can reduce cooling efficiency, but airflow may still be adequate)

Answer

Leaking refrigerant (would primarily affect cooling performance)

Answer

Faulty blower motor (would likely result in no airflow)

Question 42

When determining the correct refrigerant charge for an automotive air conditioning system, it is crucial to:

Accepted Answer

Refer to the manufacturer's specifications

Answer

Ignore the manufacturer's specifications (can void warranties and cause system damage)

Answer

Use a fixed amount based on system size (can lead to over or undercharging)

Answer

Estimate based on previous experience (unreliable and can compromise system performance)

Question 43

In a refrigeration system, which component is responsible for releasing heat into the surrounding environment?

Accepted Answer

Condenser

Answer

Compressor

Answer

Thermostat

Answer

Evaporator

Question 44

Which type of refrigerant is predominantly utilized in automotive air conditioning systems?

Accepted Answer

HFC-134a

Answer

CFC-12

Answer

Ammonia

Answer

R-22

Question 45

When diagnosing an HVAC system, which instrument is used to measure the pressure of the refrigerant?

Accepted Answer

Refrigerant manifold gauge

Answer

Tire pressure gauge

Answer

Multimeter

Answer

Voltmeter

Question 46

In a refrigerant manifold gauge setup, what does the 'low-side' gauge measure?

Accepted Answer

Pressure in the evaporator

Answer

Temperature in the condenser

Answer

Temperature in the evaporator

Answer

Pressure in the condenser

Question 47

Which of the following is a prevalent cause of inadequate airflow in an automotive HVAC system?

Accepted Answer

Clogged cabin air filter

Answer

Leaky condenser

Answer

Low refrigerant charge

Answer

Faulty compressor

Question 48

In an automotive air conditioning system, what is the primary function of the expansion valve?

Accepted Answer

Regulates refrigerant flow to the evaporator

Answer

Compress the refrigerant

Answer

Filter the refrigerant

Answer

Release heat from the refrigerant

Question 49

In an automotive HVAC system, what is the primary function of the accumulator?

Accepted Answer

Stores liquid refrigerant

Answer

Lubricates the compressor

Answer

Filters the refrigerant

Answer

Cools the refrigerant

Question 50

A technician is working on an air conditioning system that is blowing warm air.  Which of the following is the LEAST likely cause of this issue?

Accepted Answer

Low engine coolant level

Answer

Blocked condenser fins

Answer

Faulty compressor clutch

Answer

Low refrigerant charge

Question 51

Which component in an HVAC system is responsible for converting refrigerant from a low-pressure gas to a high-pressure gas?

Accepted Answer

Compressor

Answer

Condenser

Answer

Evaporator

Answer

Receiver/Drier

Question 52

What is the primary function of the receiver/drier in an HVAC system?

Accepted Answer

To remove moisture and filter debris from the refrigerant

Answer

To regulate the flow of refrigerant into the evaporator

Answer

To cool the refrigerant before it enters the evaporator

Answer

To increase the pressure of the refrigerant before it enters the compressor

Question 53

A technician is using a manifold gauge set to check refrigerant charge.  The low-side pressure reading is normal, but the high-side pressure is extremely high. What is the most likely cause of this issue?

Accepted Answer

Blocked condenser fins

Answer

Faulty compressor clutch

Answer

Low refrigerant charge

Answer

Leaking evaporator

Question 54

What is the main function of the expansion valve in an HVAC system?

Accepted Answer

To regulate the flow of refrigerant into the evaporator

Answer

To absorb heat from the cabin air

Answer

To convert refrigerant from liquid to vapor

Answer

To compress the refrigerant vapor

Question 55

While inspecting an HVAC system, you notice oily residue around a fitting. What is this most likely an indication of?

Accepted Answer

Refrigerant leak

Answer

Excessive pressure in the system

Answer

Normal operation

Answer

Clogged air filter

Question 56

Before working on any HVAC system, it is crucial to:

Accepted Answer

Evacuate the system using a recovery machine

Answer

Release all refrigerant into the atmosphere

Answer

Check the air filter

Answer

Add refrigerant to the system

Question 57

When replacing an AC compressor, which component should also be replaced as a best practice?

Accepted Answer

Receiver/drier

Answer

Blower motor

Answer

Evaporator

Answer

Thermostat

Question 58

What is the primary function of the evaporator in an HVAC system?

Accepted Answer

To absorb heat from the cabin air

Answer

To compress the refrigerant vapor

Answer

To store refrigerant

Answer

To release heat to the outside air