RETA CARO EXAM PRACTICE TEST QUESTIONS AND
CORRECT ANSWERS 2026-2027!!
Conduction is defined as heat energy that is - ANSWER moving through a solid
substance
What is the primary purpose of a refrigeration system ? - ANSWER achieve and
maintain a temperature
What is a hazard of trapping liquid ? - ANSWER A possible release
How much can the pressure of trapped liquid increase per degree Fahrenheit of
temperature increase - ANSWER 100 to 150 psi
Mechanical refrigeration is a series of steps that - ANSWER moves heat energy
from a space or object to an area where it can do no harm
How does the refrigeration compressor maintain the temperature in the system
evaporators ? - ANSWER Drawing out vaporized refrigerant at a rate to maintain
the desired evaporating pressure
Which natural refrigerant is considered to be non- flammable - ANSWER Carbon
Dioxide
Heat energy always flows - ANSWER from an object at a higher temperature to an
object at a lower temperature
32 psia equals - ANSWER 17.3 psig
0 ° F is equal to - ANSWER -18 ° C
Why does the refrigerant in the condenser change state from vapor to liquid -
ANSWER The refrigerant loses heat energy to the surrounding environment
If a liquid is below its saturation temperature what is its condition ? - ANSWER
Subcooled
What are the four necessary components of a mechanical refrigeration system ? -
ANSWER expansion device , evaporator , compressor , condenser
Superheat is found at which points of a typical system ? - ANSWER The
compressor suction and compressor discharge line
, What are the replacement blended refrigerants called ? - ANSWER An azeotrope
or zeotrope
What is one positive characteristic of halocarbon refrigerants ? - ANSWER They
are usually not flammable
What is the primary reason for concern about HCFC- 22 concentration in an
engine room ? - ANSWER Oxygen deprivation
O psig is equal to - ANSWER 14.7 psia
Discharge vapor from all compressors - ANSWER will contain some level of
superheat
Which category of compressor " traps " a volume of refrigerant vapor prior to
compression ? - ANSWER Positive displacement
When suction pressure rises , the operator should - ANSWER start another
compressor
The crankcase oil heater should be ON - ANSWER when the compressor is off .
Slugging is caused by - ANSWER oil or liquid refrigerant
What should be done if liquid refrigerant appears while draining oil ? - ANSWER
Do what the SOP states
Proper oil management for a refrigeration system requires that - ANSWER a log
should record all oil added to and removed from a system
When heat is added to saturated liquid refrigerant it will always - ANSWER
evaporate
What effect does the addition of fins to evaporator coils have ? - ANSWER It
increases the efficiency of a unit by increasing the surface area
During hot gas defrost - ANSWER high pressure gas flows through and
condenses in the evaporator
Evaporative condensers - ANSWER derive their heat rejection capability from the
evaporation of water
Air cooled condensers usually have - ANSWER higher head pressures than
evaporative condensers
CORRECT ANSWERS 2026-2027!!
Conduction is defined as heat energy that is - ANSWER moving through a solid
substance
What is the primary purpose of a refrigeration system ? - ANSWER achieve and
maintain a temperature
What is a hazard of trapping liquid ? - ANSWER A possible release
How much can the pressure of trapped liquid increase per degree Fahrenheit of
temperature increase - ANSWER 100 to 150 psi
Mechanical refrigeration is a series of steps that - ANSWER moves heat energy
from a space or object to an area where it can do no harm
How does the refrigeration compressor maintain the temperature in the system
evaporators ? - ANSWER Drawing out vaporized refrigerant at a rate to maintain
the desired evaporating pressure
Which natural refrigerant is considered to be non- flammable - ANSWER Carbon
Dioxide
Heat energy always flows - ANSWER from an object at a higher temperature to an
object at a lower temperature
32 psia equals - ANSWER 17.3 psig
0 ° F is equal to - ANSWER -18 ° C
Why does the refrigerant in the condenser change state from vapor to liquid -
ANSWER The refrigerant loses heat energy to the surrounding environment
If a liquid is below its saturation temperature what is its condition ? - ANSWER
Subcooled
What are the four necessary components of a mechanical refrigeration system ? -
ANSWER expansion device , evaporator , compressor , condenser
Superheat is found at which points of a typical system ? - ANSWER The
compressor suction and compressor discharge line
, What are the replacement blended refrigerants called ? - ANSWER An azeotrope
or zeotrope
What is one positive characteristic of halocarbon refrigerants ? - ANSWER They
are usually not flammable
What is the primary reason for concern about HCFC- 22 concentration in an
engine room ? - ANSWER Oxygen deprivation
O psig is equal to - ANSWER 14.7 psia
Discharge vapor from all compressors - ANSWER will contain some level of
superheat
Which category of compressor " traps " a volume of refrigerant vapor prior to
compression ? - ANSWER Positive displacement
When suction pressure rises , the operator should - ANSWER start another
compressor
The crankcase oil heater should be ON - ANSWER when the compressor is off .
Slugging is caused by - ANSWER oil or liquid refrigerant
What should be done if liquid refrigerant appears while draining oil ? - ANSWER
Do what the SOP states
Proper oil management for a refrigeration system requires that - ANSWER a log
should record all oil added to and removed from a system
When heat is added to saturated liquid refrigerant it will always - ANSWER
evaporate
What effect does the addition of fins to evaporator coils have ? - ANSWER It
increases the efficiency of a unit by increasing the surface area
During hot gas defrost - ANSWER high pressure gas flows through and
condenses in the evaporator
Evaporative condensers - ANSWER derive their heat rejection capability from the
evaporation of water
Air cooled condensers usually have - ANSWER higher head pressures than
evaporative condensers
