NEVADA C-21B AIR CONDITIONING CONTRACTOR ACTUAL
PRACTICE EXAM 2026/2027 QUESTIONS WITH VERIFIED
ANSWERS | INSTANT DOWNLOAD PDF
Question 1. Which of the following is the primary function of the compressor in a
refrigeration system?
A. To absorb heat from the refrigerated space
B. To raise the pressure and temperature of the refrigerant vapor
C. To reject heat to the atmosphere
D. To regulate the flow of refrigerant into the evaporator
Correct Answer: B
Rationale:
The compressor is the heart of the refrigeration system. Its primary function is to draw in
low-pressure, low-temperature refrigerant vapor from the evaporator and compress it
into a high-pressure, high-temperature vapor. This high-pressure vapor then flows to
the condenser where it can reject heat. Option A describes the evaporator. Option C
describes the condenser. Option D describes the metering device (expansion valve).
Question 2. In a refrigeration cycle, what is the function of the condenser?
A. To absorb heat from the space being cooled
B. To compress the refrigerant vapor
C. To reject heat from the refrigerant to the outside air or water
D. To reduce the pressure of the liquid refrigerant
Correct Answer: C
Rationale:
The condenser receives high-pressure, high-temperature refrigerant vapor from the
compressor. It allows the refrigerant to cool and condense into a liquid by rejecting heat
,to the surrounding air or water. Option A is the evaporator. Option B is the compressor.
Option D is the metering device.
Question 3. What is the purpose of the metering device in a refrigeration system?
A. To increase the pressure of the refrigerant
B. To control the flow of refrigerant into the evaporator and reduce its pressure
C. To absorb heat from the refrigerated space
D. To reject heat to the atmosphere
Correct Answer: B
Rationale:
The metering device (e.g., thermostatic expansion valve, capillary tube) regulates the
flow of liquid refrigerant into the evaporator. It also creates a pressure drop, which
lowers the refrigerant's temperature and allows it to absorb heat in the evaporator.
Option A is the compressor. Option C is the evaporator. Option D is the condenser.
Question 4. Which of the following refrigerants is classified as a
hydrofluorocarbon (HFC) and has been commonly used as a replacement for R-22?
A. R-134a
B. R-410A
C. R-22
D. R-12
Correct Answer: B
Rationale:
R-410A is an HFC refrigerant blend commonly used in new residential and commercial
air conditioning systems as a replacement for R-22. R-134a (A) is also an HFC but used
more in automotive and medium-temperature refrigeration. R-22 (C) is a
hydrochlorofluorocarbon (HCFC). R-12 (D) is a chlorofluorocarbon (CFC).
,Question 5. Under EPA Section 608 regulations, what is required for a technician to
purchase refrigerant?
A. A valid driver's license
B. EPA Section 608 certification
C. A business license
D. A state HVAC license
Correct Answer: B
Rationale:
EPA Section 608 certification is required for technicians who purchase, handle, or
dispose of refrigerants. This certification ensures they understand the environmental
regulations and safe handling procedures. Options A, C, and D are not sufficient for
purchasing refrigerant.
Question 6. What is the maximum allowable leak rate for commercial refrigeration
equipment under EPA regulations?
A. 5%
B. 10%
C. 20%
D. 35%
Correct Answer: C
Rationale:
Under EPA regulations (40 CFR Part 82), the maximum allowable leak rate for
commercial refrigeration equipment is 20% of the charge per year. For industrial process
refrigeration, it is 30%. For comfort cooling, it is 10%. Options A, B, and D are incorrect
for commercial refrigeration.
Question 7. In Nevada, what is the maximum contract amount a C-21B Air
Conditioning Contractor can perform without a license?
, A. $500
B. $1,000
C. $2,000
D. $5,000
Correct Answer: B
Rationale:
Nevada Revised Statutes (NRS) 624.700 states that a person may not act as a contractor
without a license if the total contract price is $1,000 or more. This applies to all
classifications, including C-21B. Options A, C, and D are incorrect thresholds.
Question 8. Which of the following is NOT a requirement for obtaining a Nevada
C-21B Air Conditioning Contractor license?
A. Four years of documented experience
B. Passing the trade exam
C. Passing the business and law exam
D. A college degree in engineering
Correct Answer: D
Rationale:
To obtain a Nevada C-21B license, applicants must have four years of documented
experience (A), pass the trade exam (B), and pass the business and law exam (C). A
college degree (D) is not required, though it may substitute for some experience in
certain cases.
Question 9. What is the primary purpose of a thermostatic expansion valve (TXV)?
A. To maintain a constant evaporator superheat
B. To maintain a constant condenser pressure
C. To maintain a constant compressor amperage
D. To maintain a constant room temperature
PRACTICE EXAM 2026/2027 QUESTIONS WITH VERIFIED
ANSWERS | INSTANT DOWNLOAD PDF
Question 1. Which of the following is the primary function of the compressor in a
refrigeration system?
A. To absorb heat from the refrigerated space
B. To raise the pressure and temperature of the refrigerant vapor
C. To reject heat to the atmosphere
D. To regulate the flow of refrigerant into the evaporator
Correct Answer: B
Rationale:
The compressor is the heart of the refrigeration system. Its primary function is to draw in
low-pressure, low-temperature refrigerant vapor from the evaporator and compress it
into a high-pressure, high-temperature vapor. This high-pressure vapor then flows to
the condenser where it can reject heat. Option A describes the evaporator. Option C
describes the condenser. Option D describes the metering device (expansion valve).
Question 2. In a refrigeration cycle, what is the function of the condenser?
A. To absorb heat from the space being cooled
B. To compress the refrigerant vapor
C. To reject heat from the refrigerant to the outside air or water
D. To reduce the pressure of the liquid refrigerant
Correct Answer: C
Rationale:
The condenser receives high-pressure, high-temperature refrigerant vapor from the
compressor. It allows the refrigerant to cool and condense into a liquid by rejecting heat
,to the surrounding air or water. Option A is the evaporator. Option B is the compressor.
Option D is the metering device.
Question 3. What is the purpose of the metering device in a refrigeration system?
A. To increase the pressure of the refrigerant
B. To control the flow of refrigerant into the evaporator and reduce its pressure
C. To absorb heat from the refrigerated space
D. To reject heat to the atmosphere
Correct Answer: B
Rationale:
The metering device (e.g., thermostatic expansion valve, capillary tube) regulates the
flow of liquid refrigerant into the evaporator. It also creates a pressure drop, which
lowers the refrigerant's temperature and allows it to absorb heat in the evaporator.
Option A is the compressor. Option C is the evaporator. Option D is the condenser.
Question 4. Which of the following refrigerants is classified as a
hydrofluorocarbon (HFC) and has been commonly used as a replacement for R-22?
A. R-134a
B. R-410A
C. R-22
D. R-12
Correct Answer: B
Rationale:
R-410A is an HFC refrigerant blend commonly used in new residential and commercial
air conditioning systems as a replacement for R-22. R-134a (A) is also an HFC but used
more in automotive and medium-temperature refrigeration. R-22 (C) is a
hydrochlorofluorocarbon (HCFC). R-12 (D) is a chlorofluorocarbon (CFC).
,Question 5. Under EPA Section 608 regulations, what is required for a technician to
purchase refrigerant?
A. A valid driver's license
B. EPA Section 608 certification
C. A business license
D. A state HVAC license
Correct Answer: B
Rationale:
EPA Section 608 certification is required for technicians who purchase, handle, or
dispose of refrigerants. This certification ensures they understand the environmental
regulations and safe handling procedures. Options A, C, and D are not sufficient for
purchasing refrigerant.
Question 6. What is the maximum allowable leak rate for commercial refrigeration
equipment under EPA regulations?
A. 5%
B. 10%
C. 20%
D. 35%
Correct Answer: C
Rationale:
Under EPA regulations (40 CFR Part 82), the maximum allowable leak rate for
commercial refrigeration equipment is 20% of the charge per year. For industrial process
refrigeration, it is 30%. For comfort cooling, it is 10%. Options A, B, and D are incorrect
for commercial refrigeration.
Question 7. In Nevada, what is the maximum contract amount a C-21B Air
Conditioning Contractor can perform without a license?
, A. $500
B. $1,000
C. $2,000
D. $5,000
Correct Answer: B
Rationale:
Nevada Revised Statutes (NRS) 624.700 states that a person may not act as a contractor
without a license if the total contract price is $1,000 or more. This applies to all
classifications, including C-21B. Options A, C, and D are incorrect thresholds.
Question 8. Which of the following is NOT a requirement for obtaining a Nevada
C-21B Air Conditioning Contractor license?
A. Four years of documented experience
B. Passing the trade exam
C. Passing the business and law exam
D. A college degree in engineering
Correct Answer: D
Rationale:
To obtain a Nevada C-21B license, applicants must have four years of documented
experience (A), pass the trade exam (B), and pass the business and law exam (C). A
college degree (D) is not required, though it may substitute for some experience in
certain cases.
Question 9. What is the primary purpose of a thermostatic expansion valve (TXV)?
A. To maintain a constant evaporator superheat
B. To maintain a constant condenser pressure
C. To maintain a constant compressor amperage
D. To maintain a constant room temperature
