Texas ACR Contractor Exam (Class B) Examination
Verified Questions, Correct Answers, and Detailed
Explanations for Science Students||Already Graded
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1. Class B licensing allows work on systems up to what cooling
capacity?
A. 10 tons
B. 15 tons
C. 25 tons
D. Unlimited
Answer: C. 25 tons
Class B contractors are limited to cooling systems of 25 tons or less
and heating systems of 1.5 million BTU/hr or less.
2. The primary purpose of superheat is to:
A. Increase compressor pressure
B. Ensure no liquid enters the compressor
C. Reduce condenser temperature
D. Improve airflow
Answer: B. Ensure no liquid enters the compressor
Superheat confirms that refrigerant is fully vaporized before reaching
the compressor, preventing damage.
3. Subcooling occurs in the:
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
,Answer: C. Condenser
Subcooling is the process of cooling liquid refrigerant below its
saturation temperature in the condenser.
4. The component that meters refrigerant into the evaporator is
the:
A. Filter drier
B. Expansion device
C. Accumulator
D. Receiver
Answer: B. Expansion device
TXVs, cap tubes, and pistons regulate refrigerant flow into the
evaporator.
5. R-410A operates at pressures that are:
A. Lower than R-22
B. The same as R-22
C. Higher than R-22
D. Vacuum only
Answer: C. Higher than R-22
R-410A systems require equipment rated for significantly higher
pressures.
6. The most common cause of compressor failure is:
A. Dirty condenser
B. Floodback or liquid slugging
C. High airflow
D. Oversized duct
,Answer: B. Floodback or liquid slugging
Liquid refrigerant entering the compressor can cause mechanical
damage.
7. A system with high head pressure may be caused by:
A. Low airflow across condenser
B. Low refrigerant charge
C. Low ambient temperature
D. Dirty evaporator
Answer: A. Low airflow across condenser
Restricted condenser airflow raises condensing temperature and
pressure.
8. The EPA Section 608 certification is required to:
A. Install ductwork
B. Handle refrigerants
C. Perform electrical work
D. Size equipment
Answer: B. Handle refrigerants
Federal law requires certification to purchase or handle regulated
refrigerants.
9. The purpose of a filter drier is to remove:
A. Oil only
B. Airflow restrictions
C. Moisture and contaminants
D. Heat
, Answer: C. Moisture and contaminants
Moisture can form acids and ice, damaging the system.
10. A TXV controls refrigerant flow based on:
A. Head pressure
B. Suction pressure only
C. Evaporator superheat
D. Ambient temperature
Answer: C. Evaporator superheat
TXVs adjust flow to maintain proper superheat at the evaporator
outlet.
11. The unit of electrical power is:
A. Volt
B. Amp
C. Ohm
D. Watt
Answer: D. Watt
Power equals volts × amps.
12. Ohm’s Law states:
A. V = I × R
B. V = P × I
C. I = V × R
D. R = I × V
Answer: A. V = I × R
Voltage equals current multiplied by resistance.
Verified Questions, Correct Answers, and Detailed
Explanations for Science Students||Already Graded
A+
1. Class B licensing allows work on systems up to what cooling
capacity?
A. 10 tons
B. 15 tons
C. 25 tons
D. Unlimited
Answer: C. 25 tons
Class B contractors are limited to cooling systems of 25 tons or less
and heating systems of 1.5 million BTU/hr or less.
2. The primary purpose of superheat is to:
A. Increase compressor pressure
B. Ensure no liquid enters the compressor
C. Reduce condenser temperature
D. Improve airflow
Answer: B. Ensure no liquid enters the compressor
Superheat confirms that refrigerant is fully vaporized before reaching
the compressor, preventing damage.
3. Subcooling occurs in the:
A. Evaporator
B. Compressor
C. Condenser
D. Expansion valve
,Answer: C. Condenser
Subcooling is the process of cooling liquid refrigerant below its
saturation temperature in the condenser.
4. The component that meters refrigerant into the evaporator is
the:
A. Filter drier
B. Expansion device
C. Accumulator
D. Receiver
Answer: B. Expansion device
TXVs, cap tubes, and pistons regulate refrigerant flow into the
evaporator.
5. R-410A operates at pressures that are:
A. Lower than R-22
B. The same as R-22
C. Higher than R-22
D. Vacuum only
Answer: C. Higher than R-22
R-410A systems require equipment rated for significantly higher
pressures.
6. The most common cause of compressor failure is:
A. Dirty condenser
B. Floodback or liquid slugging
C. High airflow
D. Oversized duct
,Answer: B. Floodback or liquid slugging
Liquid refrigerant entering the compressor can cause mechanical
damage.
7. A system with high head pressure may be caused by:
A. Low airflow across condenser
B. Low refrigerant charge
C. Low ambient temperature
D. Dirty evaporator
Answer: A. Low airflow across condenser
Restricted condenser airflow raises condensing temperature and
pressure.
8. The EPA Section 608 certification is required to:
A. Install ductwork
B. Handle refrigerants
C. Perform electrical work
D. Size equipment
Answer: B. Handle refrigerants
Federal law requires certification to purchase or handle regulated
refrigerants.
9. The purpose of a filter drier is to remove:
A. Oil only
B. Airflow restrictions
C. Moisture and contaminants
D. Heat
, Answer: C. Moisture and contaminants
Moisture can form acids and ice, damaging the system.
10. A TXV controls refrigerant flow based on:
A. Head pressure
B. Suction pressure only
C. Evaporator superheat
D. Ambient temperature
Answer: C. Evaporator superheat
TXVs adjust flow to maintain proper superheat at the evaporator
outlet.
11. The unit of electrical power is:
A. Volt
B. Amp
C. Ohm
D. Watt
Answer: D. Watt
Power equals volts × amps.
12. Ohm’s Law states:
A. V = I × R
B. V = P × I
C. I = V × R
D. R = I × V
Answer: A. V = I × R
Voltage equals current multiplied by resistance.
