CARO PRACTICE EXAM QUESTIONS
AND ANSWERS 2025/2026
Which of these is equivalent to 150 PSIA?
A. 164.7 PSIG
B. 185.0 PSIG
C. 135.3 PSIG
D. 121.7 PSIG - ANSWERSC
What is the volume of a cold storage room that is 150' long, 80' wide and 35' high?
A. 12,000 cubic feet
B. 219,000 cubic feet
C. 392,000 cubic feet
D. 420,000 cubic feet - ANSWERSD
What is required to move heat from one object to another?
A. Change of state
B. Heat of fusion
C. Latent heat
D. Temperature difference - ANSWERSD
What does temperature indicate?
A. The quantity of heat energy in an object
B. Intensity of heat energy in an object
C. Latent heat energy of an object
D. The pressure of a vapor - ANSWERSB
How much heat must be removed to convert 5 pounds of water that is at 32°F to ice at
20°F?
Q2=m⋅c⋅ΔT
Where:
Q2 = heat removed (BTUs)
m = mass of the ice (in pounds)
c = specific heat of ice (approximately 0.5 BTU/lb°F)
Delta TΔ = change in temperature (final temperature - initial temperature) -
ANSWERS750 btu
Which of these is required to obtain a valid reading from a pressure/temperature chart?
A. The refrigerant must be in a saturated condition.
B. The refrigerant must be in a superheated condition.
C. The refrigerant must be at a constant temperature.
D. The refrigerant must be in a sub-cooled condition. - ANSWERSA
, What does the term "compression ratio" refer to?
A. The ratio of piston length to piston diameter
B. The ratio of discharge pressure to suction pressure in PSIA
C. The ratio of discharge pressure to suction pressure in PSIG
D. The ratio of suction gas volume to discharge gas volume - ANSWERSB
Which of these is an essential component of a mechanical refrigeration system?
A. Accumulator
B. Receiver
C. Thermostat
D. Expansion device - ANSWERSD
What is a function of the compressor in a mechanical refrigeration system?
A. To pump liquid to the expansion device
B. To accept vapor from the evaporator and compress it to increase its pressure and
temperature
C. To remove vapor from the condenser and send it to the receiver
D. To remove liquid from the evaporator - ANSWERSB
Which of these accurately describes sub-cooled liquid?
A. Liquid at -20°F
B. Liquid at 95°F
C. Liquid cooled below its saturation pressure
D. Liquid returning from the condenser - ANSWERSC
Which refrigerant is more forgiving to moisture in a refrigeration system?
A. R-507
B. HCFC-22
C. R-134a
D. R-717 - ANSWERSB
What is the greatest risk from closing valves on each end of a liquid line between a
liquid pump and an evaporator during maintenance of an ammonia refrigeration
system?
A. Collapse of the line if the liquid cools more than a few degrees
B. Excessive discharge temperature when the line is reopened
C. Rupture of the line if the liquid warms
D. Inadequate pressure in the line when the line is reopened - ANSWERSA
Under what conditions do halocarbon refrigerants become most hazardous?
A. When they are compressed
B. When they come in contact with an open flame
C. When they are cooled
D. When oil is present at condensing temperatures - ANSWERSB
Which refrigerant is more forgiving to moisture in a refrigeration system?
AND ANSWERS 2025/2026
Which of these is equivalent to 150 PSIA?
A. 164.7 PSIG
B. 185.0 PSIG
C. 135.3 PSIG
D. 121.7 PSIG - ANSWERSC
What is the volume of a cold storage room that is 150' long, 80' wide and 35' high?
A. 12,000 cubic feet
B. 219,000 cubic feet
C. 392,000 cubic feet
D. 420,000 cubic feet - ANSWERSD
What is required to move heat from one object to another?
A. Change of state
B. Heat of fusion
C. Latent heat
D. Temperature difference - ANSWERSD
What does temperature indicate?
A. The quantity of heat energy in an object
B. Intensity of heat energy in an object
C. Latent heat energy of an object
D. The pressure of a vapor - ANSWERSB
How much heat must be removed to convert 5 pounds of water that is at 32°F to ice at
20°F?
Q2=m⋅c⋅ΔT
Where:
Q2 = heat removed (BTUs)
m = mass of the ice (in pounds)
c = specific heat of ice (approximately 0.5 BTU/lb°F)
Delta TΔ = change in temperature (final temperature - initial temperature) -
ANSWERS750 btu
Which of these is required to obtain a valid reading from a pressure/temperature chart?
A. The refrigerant must be in a saturated condition.
B. The refrigerant must be in a superheated condition.
C. The refrigerant must be at a constant temperature.
D. The refrigerant must be in a sub-cooled condition. - ANSWERSA
, What does the term "compression ratio" refer to?
A. The ratio of piston length to piston diameter
B. The ratio of discharge pressure to suction pressure in PSIA
C. The ratio of discharge pressure to suction pressure in PSIG
D. The ratio of suction gas volume to discharge gas volume - ANSWERSB
Which of these is an essential component of a mechanical refrigeration system?
A. Accumulator
B. Receiver
C. Thermostat
D. Expansion device - ANSWERSD
What is a function of the compressor in a mechanical refrigeration system?
A. To pump liquid to the expansion device
B. To accept vapor from the evaporator and compress it to increase its pressure and
temperature
C. To remove vapor from the condenser and send it to the receiver
D. To remove liquid from the evaporator - ANSWERSB
Which of these accurately describes sub-cooled liquid?
A. Liquid at -20°F
B. Liquid at 95°F
C. Liquid cooled below its saturation pressure
D. Liquid returning from the condenser - ANSWERSC
Which refrigerant is more forgiving to moisture in a refrigeration system?
A. R-507
B. HCFC-22
C. R-134a
D. R-717 - ANSWERSB
What is the greatest risk from closing valves on each end of a liquid line between a
liquid pump and an evaporator during maintenance of an ammonia refrigeration
system?
A. Collapse of the line if the liquid cools more than a few degrees
B. Excessive discharge temperature when the line is reopened
C. Rupture of the line if the liquid warms
D. Inadequate pressure in the line when the line is reopened - ANSWERSA
Under what conditions do halocarbon refrigerants become most hazardous?
A. When they are compressed
B. When they come in contact with an open flame
C. When they are cooled
D. When oil is present at condensing temperatures - ANSWERSB
Which refrigerant is more forgiving to moisture in a refrigeration system?
