ACR-120 Basic A/C Final Exam Problems
UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
1. The correct way to short capacitor terminals before checking a capacitor with an ohmmeter
is to use a _______ ohm resistor. - CORRECT ANSWER 20,000
2. Fractionation occurs when __________ - CORRECT ANSWER some of a blended
refrigerant evaporates or condenses before the rest of the blend.
3. Refrigerant in vapor form is normally put into the system through the ______. -
CORRECT ANSWER suction line.
4. When charging a system with vapor refrigerant from a refrigerant cylinder, the cylinder
will become ___________. - CORRECT ANSWER cold.
5. When moisture is present in a refrigeration system, it will react with the refrigerant and the
oil to form ________. - CORRECT ANSWER acid.
6. Which of the following represents the lowest vacuum? - CORRECT ANSWER 1000
microns
7. To pull a vacuum means to ____________. - CORRECT ANSWER lower the
pressure in a refrigeration system below atmospheric.
8. The best method of leak checking is when the refrigeration system is ________________. -
CORRECT ANSWER standing with dry nitrogen pressure of 150 psig in the system.
9. Noncondensable gases ______________. - CORRECT ANSWER are undesirable in
a refrigeration system.
, 10. If an air-conditioning system develops a refrigerant leak and the unit is not equipped with
a low pressure control, which of the following could occur? - CORRECT
ANSWER The compressor could overheat and air could get pulled into the system
11. Freezing of the evaporator coil is a symptom of ___________, ___________, and
______________. - CORRECT ANSWER a low heat load, an undercharge, and a
restricted metering device.
12. Which line in an air conditioning system holds the most refrigerant? - CORRECT
ANSWER Liquid line
13. Noncondensable gases ______________. - CORRECT ANSWER undesirable in a
refrigeration system.
14. A PSC compressor motor has ____________. - CORRECT ANSWER a run
capacitor.
15. Completely clogged air filters can lead to _____________. - CORRECT
ANSWER low evaporator fan amperage, compressor damage, and evaporator ice
formation.
16. At typical operating conditions, the standard air-conditioning system will operate with an
evaporator boiling point of _________°F. - CORRECT ANSWER 40
17. As a rule of thumb, the air leaving the evaporator will be about ___________ than the air
entering the evaporator. - CORRECT ANSWER 17-23° cooler
18. The liquid line temperature is used to determine the __________ of a condenser. -
CORRECT ANSWER subcooling
19. Superheated refrigerant is present where in a normally operating air conditioning system.
- CORRECT ANSWER Evaporator and suction line and compressor and discharge
line.
UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
1. The correct way to short capacitor terminals before checking a capacitor with an ohmmeter
is to use a _______ ohm resistor. - CORRECT ANSWER 20,000
2. Fractionation occurs when __________ - CORRECT ANSWER some of a blended
refrigerant evaporates or condenses before the rest of the blend.
3. Refrigerant in vapor form is normally put into the system through the ______. -
CORRECT ANSWER suction line.
4. When charging a system with vapor refrigerant from a refrigerant cylinder, the cylinder
will become ___________. - CORRECT ANSWER cold.
5. When moisture is present in a refrigeration system, it will react with the refrigerant and the
oil to form ________. - CORRECT ANSWER acid.
6. Which of the following represents the lowest vacuum? - CORRECT ANSWER 1000
microns
7. To pull a vacuum means to ____________. - CORRECT ANSWER lower the
pressure in a refrigeration system below atmospheric.
8. The best method of leak checking is when the refrigeration system is ________________. -
CORRECT ANSWER standing with dry nitrogen pressure of 150 psig in the system.
9. Noncondensable gases ______________. - CORRECT ANSWER are undesirable in
a refrigeration system.
, 10. If an air-conditioning system develops a refrigerant leak and the unit is not equipped with
a low pressure control, which of the following could occur? - CORRECT
ANSWER The compressor could overheat and air could get pulled into the system
11. Freezing of the evaporator coil is a symptom of ___________, ___________, and
______________. - CORRECT ANSWER a low heat load, an undercharge, and a
restricted metering device.
12. Which line in an air conditioning system holds the most refrigerant? - CORRECT
ANSWER Liquid line
13. Noncondensable gases ______________. - CORRECT ANSWER undesirable in a
refrigeration system.
14. A PSC compressor motor has ____________. - CORRECT ANSWER a run
capacitor.
15. Completely clogged air filters can lead to _____________. - CORRECT
ANSWER low evaporator fan amperage, compressor damage, and evaporator ice
formation.
16. At typical operating conditions, the standard air-conditioning system will operate with an
evaporator boiling point of _________°F. - CORRECT ANSWER 40
17. As a rule of thumb, the air leaving the evaporator will be about ___________ than the air
entering the evaporator. - CORRECT ANSWER 17-23° cooler
18. The liquid line temperature is used to determine the __________ of a condenser. -
CORRECT ANSWER subcooling
19. Superheated refrigerant is present where in a normally operating air conditioning system.
- CORRECT ANSWER Evaporator and suction line and compressor and discharge
line.
